Yes he is. One of the reasons (one of the more charitable ones out of a lot of not so nice ones) is that not infrequently, malicious plot-derailer got early and repeatedly stuck in a game that didn't have the kind of experience I'm talking about, and that's all he wanted. So seeing through the illusion, he started poking holes in it.
I'm sure it doesn't make the DM feel any better, with a pit bull jaws wrapped around his forearm, to know that the pit bull only got that way because someone was beating it with a stick earlier. And it doesn't change that it would be better for all concerned if the pit bull stopped. It does change the perspective a bit to learn that the guy getting bit was one of the guys with the earlier stick.
But beyond that, I say that with that opening statement, your definition of "meaningful plot choices" is too narrow to match the expectations of most of the players in my experience, and too limited on what constitutes narrative.
Look, let's take it from the hindsight perspective. Let's say that we had a game earlier this year where Brave Sir Robin was in a climatic situation, and confronted with a nasty choice. He could hold off the orcs at the gate, given his friends time to escape, but probably die himself. Or he could run with his friends, run a very real but smaller risk that they will all die--and this goes against the nature of the character he has been portraying.
That is a bit of the rough narrative, after the fact. Merely from that, we don't know how the game was run. This whole thing might have been a blatant railroad. Heck, Robin's player might have asked for it be contrived this way, just so that he could react to it. Or it might have simply been a situation that came up organically, through Robin's and the other players' choices. Or their bad luck, misunderstandings, etc. Or any number of things. But simply from the narrative, we don't know.
Now, make some assumptions about what the players wanted.
A. The players were primarily interested in doing characterization while being involved in a story. Robin's player had background or other hints that emphasizes that he wants to wrestle with doing what is honorable and risky in character, versus what is expedient as a player. He wants to be put into situations very much like the one above. The DM plots out a Moria-style dungeon, overwhelming odds, and narrow places to be held. Or if he knows the players are fine with this, he might even do a climatic encounter near the end of this dungeon, and manipulate things so that Robin gets to make his choice.
Robin makes his choice. Either way, we are going to have some survivors at least, to continue the story that is being told.
This is a meaningful choice for Robin. It is not a meaningful choice in the outcome of the narrative. It is a meaningful choice in the characterization of Robin by that player. A very meaningful one--and one he has explicitly planned on making. In fact, it is so explicit that the DM, if he has any sense, has probably included in his plot ways for that choice to ripple a bit. (He has expected that Robin may die at a key moment, or alternately may be consumed by doubt having fled such a challenge.) But Robin's player, when he makes his choice, as far as the plot is concerned, is picking between the door on the left and the door on the right, with no clue what is behind either door.
B. The players were primarily interested in making meaningful choices that change the results of the story. As it happens, Robin's player in this version still wants to do some of the same kinds of characterization, but this is secondary to changing the trajectory of the story itself. The DM may or may not provide that same dungeon. It doesn't matter. Wherever Robin goes, there are monsters and NPCs that are going to push him, so that he will be granted opportunities to make those kind of choices.
So Robin gets put into situations like this on a regular basis. If he keeps going all heroic, chances are he eventually dies. His dying may save the rest of the party. Or it may doom them, should he pick a moment poorly.
The characterization has happened all along. The characterization was not a meaningful choice. Run now and doubt, you'll get another chance tomorrow to stand and fight, perchance to die or narrowly escape. In the story, the choices have all been meaningful.
Finally, note that while I have leaned on the possibility of death to make this (I hope) clear, such distinctions are not limited to dying or not. It is not terribly difficult to make monsters with goals and motivations such that the PCs want to oppose them (or at least investigate that possibility) without directly fighting them. Therefore, it is not difficult to build a web of monsters that, over time, will spark some real conflict.