Emphasis mine...This right here says that turns are used in combat but are also used in other situations outside of combat...
It implies that, sure. Do we get any actual rules or examples, or is it just another area where the DM is left plenty of latitude to fill things in?
...and, you'll note, I did lampshade that RAW isn't exactly the best way to interpret 5e...
So there are times in non-combat situations where action surge is useful, IMO...mainly when distance and time are a factor.
Yep, you might have to win a foot race or something now and then. They're not necessarily at all common, but in those corner cases it could come up. Action Surge is a very potent combat resource to sacrifice, though, and, for instance, the Rogue might pull similar tricks with the extra Dash from Cunning Action - and that's not a limited resource, it's 1/rnd.
Strangely enough the main complaint about the fighter, even the 4e fighter, has been a lack of versatility...
Certainly one of them. The 3.5 optimization Tiers for instance, were at least as much a ranking by versatility as by power, though the fighter scored low on both, and 'Fighter SUX' threads of the day were more often about how CoDzilla could out-fighter-the-fighter rather than the fighter being unable to meld into stone or whatever. Similarly, the 4e fighter was far more harshly criticized for 'casting spells' or 'controlling minds' than for lacking ritual casting.
But, in this case, increased versatility could directly address the particular topic of this thread, for instance.
I would assume it's the same subset complaining about this (since it's the same complaint every time) and claiming the class is an example of "bad design"... what that seems to imply is that it's a minority of D&D players
Yes, the folks vocally complaining about a problem are usually a small, well,
vocal minority. That doesn't make them wrong, automatically, it's the validity of the complaint that determines that.
... again for the majority of players of D&D.
... again,
argumentum ad populum. You can't argue "the fighter is popular because it's good, and, as proof, observe that it must be good, because it's popular!" Or rather, you can, and have, repeatedly, it's just transparently bad reasoning. If you want to argue the conclusion that the fighter is popular because it's design is good, you'll have to demonstrate that both premises: both 'popular,' and 'good design,' are true, without referencing the one to 'prove' the other.
Popular's easy.
'Good design?' Good luck. I'd rather defend the 3.x fighter on that one, subjective as 'elegance' can be as a design virtue....