Because it’s not like 5e is any more simulationist than 4e. So if people dropped 4e because it wasn’t sim enough, why does 5e get the pass?
Quite frankly, I think this argument is bizarre. 5E
is more simulationist than 4E; again, does 5E have damage on a miss? No? Well, that's a highly gamist mechanic which – by virtue of confusing the issue about whether or not hit point loss is injury or stamina reduction – negatively impacts the simulationist aspect of play. Since 5E doesn't have it (or related mechanics, such as "minion" monsters who are defeated if they take any damage, but for some reason can't be damaged on a miss), it's therefore more simulationist.
That's a single example, to be sure, but it serves to undercut the central argument. Small changes like that abound in the 4E-to-5E comparison, but they add up to the same overall conclusion.
More broadly, however, what you seem to be asking about is why aren't people turning on 5E en masse the way they did 4E, if 5E has some of the same issues (e.g. the fighter's having a "second wind" power)?
I've seen a lot of people in this thread say that it's because people are inconsistent, and while that's true as a generality, I don't think that it's the case with regard to the 5E vs. 4E issue. Rather, it's that people (for the most part) didn't reject 4E for any
single issue; there was no one thing that made them look at it and say "I was fine with the game, but
this is a bridge too far!"
Rather, it was because 4E piled up enough straws that they eventually broke the camel's back. Most people are willing to play a game that's less than ideal/perfect/fits their conception of everything they want in an RPG. It's usually only when it breaks from
enough of their expectations that they'll throw their hands in the air and say, "nope, that's it!" They certainly might point to a single instance of where they lost their patience with it, but in virtually every circumstance, there were a lot of steps that led them to that moment, rather than one single thing taking them directly from "fine" to "I hate this."
In that regard, 5E's flaws are (to most people that I'm aware of) both less numerous and less egregious than those of 4E, and so people are willing to give it a pass enough to invest in it, or at least to not regard it as a complete betrayal of their expectations. Which makes sense, because 5E was made as a reaction to the backlash that 4E provoked, and so it's no surprise that it moved away from it in so many regards. Yes, some of the issues that its predecessor had are still there (5E took inspiration from every prior edition of the game, 4E included), but not as many, and not as extreme in their intrusiveness. Whether it was verisimilitude or having an SRD that didn't punish third parties who used it, 5E was better – or at least not as bad – as 4E.
Hence, the idea that 5E is just as bad as 4E, with its implication that the people who rallied against the latter but are fine with the former are somehow hypocrites, rings completely false to me.