Sure. But sometimes player input might result the game stalling and nothing interesting happening. Or something happening that the players actually didn't want to happen. And I don't think it is wrong for GM to nudge things into more interesting or preferable directions on such occasions.
Okay, getting the game moving again is part of the GM's job, I'd say. I mean, it's the players' job too, but if they've stalled out, the GM needs to do something to get things going again.
I don't think that constitutes Force. Or at least, it certainly doesn't require it.
Certainly letting them to find it in the next place they look effectively is the GM letting them find it? The illusion just is that the players feel they did something to contribute to it, whilst in reality they didn't. And I don't see how that is bad thing.
Again, I think this depends on the game and/or expectations. Like in early editions of D&D, that would be against expectations. But in a game that uses the Gumshoe system, it's likely not.
I personally don't like that kind of approach, but I don't think there's anything inherently wrong with it. In 5e D&D, it seems a bit against expectations, but well within the realm of possibility.
And yeah, it was a boring linear scenario and in almost every instance the use of force could be avoided by setting up the situation better in the first place. (I guess that's why I haven't had to use force in my current campaign!

) But none of us are perfect, perhaps not even me! Sometimes you set up the situation thoughtlessly, and then in actual game it just doesn't quite work. And if you can fix it by rearranging things behind curtains a bit, why not?
If painted into a corner in some way, sure, do what you have to in order to get the game going again. Again, I don't know if Force is needed, but if you find yourself in a situation where it's a bit of Force to correct the matter, or let the game flounder, then sure, Force away.
But lets say force is used to achieve this. Why is that bad?
It's hard to say. If the GM is working to bring about something of interest to the player then I'm generally of the opinion that's a good thing. Again, I don't know how Force is necessary in this case, so it's hard to say. Possibly? I mean, the benefit seems to outweigh the drawback, again depending on expectations.
Yea, but this is where it gets muddy. What even is force?
I've been using it to mean the GM overriding or otherwise negating the outcome of player decisions in favor of some other outcome.
I'm not using it as a description of the GM authoring content for the game.
Let's say this is the scenario. The player whose sister is missing is really invested to this storyline. It is the driving force of their character. This is important to the player. The characters infiltrate the cultist hideout. The PC's sister has joined the cult, but the characters don't know this, they just think that the cult has kidnapped her. Though they suspect things might not be quite as they seem. Also they have one new character. One player's character died in the previous session, and they're now playing a hot-headed fire sorcerer. Before this (and when the GM designed the scenario) the party had no AoE to speak off. They have a clever plan to get in unnoticed, but due a series of unlucky rolls and perhaps some bad decisions they get discovered just as they're about to enter the main chamber where the cultists are gathered for some sort of ritual. Unbeknownst to characters, one of the hooded cultist is the PCs sister. Some characters, including the one looking for his sister would want to negotiate, but the sorcerer, assuming that battle is about to ensue and seeing several cultist clumped together decides to take out as many of them as they can and unleashes a fireball. This fireball is powerful enough to kill any cultist who fails their save. Let's also assume that it is an established rule in this group that only PCs get death saves, and any non-PC who runs out of hit points is dead.
Assuming the GM has predetermined which cultist is the sister and she is in the fireball's area, is it force if they fudge her saving throw so that she survives? Or what if they simply 'switch' her with insignificant cultist that is standing on the edge of the room and thus are not hit? Or what if the GM designed the sisters location to be quantum cultist in the first place? Whichever cultist survives is revealed to be the character's sister when it is most appropriate? Which of these are force, and is any of this a bad thing?
And yes, I am sure the need to use force could have been avoided with better foresight, but as we now, that doesn't always happen.
I play plenty of games that don't rely on prep to the level of detail that this would be a problem as presented. So in that sense, I'm okay with the idea of having the fireballed cultists not include the sister. But in those games, there are other processes by which this could play out. The GM might place the sister there as a move in a PbtA game, or as a consequence in Blades in the Dark.
In a case where it hasn't been established in some way that she's there, I'd be more okay with a change. In this case, you're not really subverting the choice of the players since no one made the choice to fireball the sister. Having typed it, I'm not crazy about it, though.
I'd likely set things up quite differently. I'm not really interested in keeping that kind of information from the players. My D&D games likely feature far fewer Perception checks than many others. I tend to just tell players things. Why not? I want to see what they do with the info, I don't want to watch them slowly piece it together by asking me questions and then rolling a dice and asking me more questions. So I'd tend to avoid such a scenario in most cases. The sister would either be there or not, and they would proceed accordingly.
I'd prefer to let it play out as is, unless I really expected things to somehow go wrong with the game as a result.
If one of the PCs has seen her, or there's some other strong reason to expect that she's there, and the sorcerer still shot the fireball off.....I wouldn't go back on that. I'd roll her save for all to see, and let things play out as they may.
I have to say that this is almost certainly a confirmation bias. You only know of the instances you noticed it! For example in the above scenario all examples of GM chicanery would be pretty much completely undetectable to the players.
Oh, I'm not claiming I always know it. Just that sometimes when consequence X is on the table, and then things go poorly, and then consequence Y is what happens.....that's obvious and that kind of softballing is what I don't appreciate. It's like when I let my kid get a basket instead of stuffing him.....I feel like the GM is turning things down a bit.
And whenever I (rarely) use something forceish, it is almost always just changing some things the players didn't know of in the first place.
I mean if we are talking about GM misleading the players, to me it would be far more questionable to GM to say that a creature is level one minion whereas in reality they're level ten solo controller, than just relay the what the characters see and that turning out not to be the whole truth.
I'm not convinced that it's the secrecy that really matters. If Force is wrong for a given game, or in a given situation, then it's wrong. Keeping the players from knowing it is just making things easy on yourself.
As for the scenario of the little girl and the stat block, it's an imperfect example to be sure because it was an example of one thing and then got adapted for another. When a game I'm GMing includes someone who's magically changed shape in some way, I give the players some way to pick up on that. I present it in another way or through a different scene. So it'd go differently.
But, I'm not nearly as concerned as many about the players knowing something's up when the characters might not.
I don't metagame and I can roleplay being surprised. But I definitely prefer to be genuinely surprised!
Yeah, I get that. And I prefer to actually surprise people. But again, if that's my intent, I'm going to go about it in a different way that will actually have the potential to surprise someone.
More importantly, the limit that this places on my ability to surprise players with some secret reveal is minimal compared to what I see as the benefit of sharing information with them. Like it's a price totally worth paying.
That little moment of surprise "Oh my gosh the little girl is actually St. Cuthbert?!?!? WHA?!?" is a moment of play. The GM sharing information with players so that they can act clearly and comfortably is a near constant part of the game.