To each his own I guess.
To me, this is the absolute number one thing I hate about DMing D&D.
And I don't think I'm quite as alone here as all that. Because, as a player or as a DM, I've noticed that those "open ended" spells are either top of DM's banned lists, or are just not taken by players. I mean, sure, illusions are great on paper. But, how many illusion spells (and I mean straight up creating image spells, not simply stuff like invisibility or hypnotic patern) have you seen cast in, say, the last ten sessions you played or ran?
Me? None. The players never use them because they're just too random. Who knows how they're going to be adjudicated? Is it going to be done with the intent of the game? Or is it going to be nothing but Monkey Paws all the way down. It's the reason I see players come to my table who will spend two hours trying to word a wish because they automatically assume that the DM will try to weasel out of it.
Last night's session was a perfect example. The party enters a temple of Vecna and there's an ongoing ritual going on. Lots of chanting and whatnot. Party Psi-fighter uses his flying power to fly into the room, which triggers the ongoing Mass Suggestion effect for anyone entering.
Me: Ok, you failed your save. The suggestion is to sit down and start praying.
Player: Ok, well, I'm in mid air, so, I stop and sit down in mid air. When my turn is up, I fall and take damage, so, I get another saving throw.
Me: Facepalm.
It's exactly that sort of crap that I detest. Cheesemonkey weaseling out of effects because I didn't write a freaking ten page contract in order to give the exact wording of the Suggestion.
And I guarantee that if I did it the other way - if the party had cast the Suggestion and I did that, they'd be the first ones to cry foul.
It just sucks any and all enjoyment out of the game for me.
This is just why the DMG (and maybe the PHB) needs to discuss things like bottlenecking and collaboration in terms DMs (and players) can quickly grok and apply, not a reason to ban all open-ended game mechanics.
If I'm worried about "cheesemonkey weaseling," I'm worried about a player behavior that's toxic to the group's dynamic, not about a game mechanic. The problem with paladins and rogues fighting each other was never really about paladins and rogues, after all. Kender players never needed the kender as an excuse. Etc.
We're often missing good game mechanics to support this pillar of play. It's an area that desperately needs work in D&D. Taking out parts of the game that are like that isn't really a solution, though.
But Command and Dissonant Whispers are almost, not quite, but almost exactly the same spells. Caster forces enemy to take an action. The only difference is Dissonant Whispers has a single, specific effect, and Command is written with vague wording because that's the way it was written in the PHB forty years ago. I mean, heck, you only have to look at how new spells are written. You don't get these vague, open ended spells because they cause nothing but problems at tables.
That's not the reason
command was written that way in 2014. I can confidently say that it was an intentional choice, not an accident.
There's good things that come from that choice.
It's not fun for me. It just isn't. It's players trying to game the system, rather than actually playing the game. People can tell me how much fun this is until the cows come home. I have zero interest in playing amateur game designer in the middle of a game session. Vague, open ended effects are simply poor game design as far as I'm concerned.
There is a vast gulf between "I don't like this," and "this is poor game design." Don't mistake preference for quality.
It also sounds like the reason you don't like this is because there's some tension between you and some players - some place where you're not agreeing on what you're sitting down at the table to do (you want a moment of a cool dungeon trap, they reject that - why?). That is a social contract problem, not a rules problem. It's still a problem D&D should be better about designing around, IMO, though it can't very well do that if it's focused on flattening the experience, either.
I mean, we don't allow this for anything other than magical effects in the game. Ever. I'm not allowed to cut off someone's hand with a great axe. Full stop. There is literally no rules in 5e D&D that let me disable a monster's claw attack. Despite the fact that there should be. If I ask the DM, "Hey, can I disable the creature's claw attack instead of dealing damage?" No DM would ever allow it. Just not going to happen.
But, as soon as I'm using a spell? Hoo Boy! I get to tell the DM all sorts of things and so long as I can convince the DM that it's okay, then I get to do it. Create Water inside a creature used to be a thing, and now it's not. Have we really lost creativity because I can no longer make a monster's head explode with a 1st level cleric spell?
Trojan horsing a martials vs. magicals argument into here is a meaningless distraction. It doesn't just move the goalposts, it imagines we're playing a whole different sport. Stay on target.
If you have an issue with open-ended mechanics, you have an issue with both the 2014
command spell and, let's say, an open-ended "called shots" system for attacks that could disable monster parts if a player opted to target a specific bit. Because players could hypothetically steamroll you and exploit some mechanical loophole you weren't prepared for in both situations ("I cut off it's head!" could end a fight real quick).
But, like,
you're the DM, so what's forcing you to agree to the exploit? Or preventing you from having it work Only Once? Or limiting your ability to say Yes And or Yes But? Why AREN'T you comfortable doing a bit of house ruling for your preferred experience?
Because I do think D&D could be a lot better about supporting those decisions, and designing things that reduce the insecurity of players and DMs. And wouldn't it be great if you COULD use all those creative illusions without fear and fragility preventing you? Because I've been at tables where it happens, and it is, IMXP, a LOT of fun.