Of course there are exceptions to the rule
I can agree with you that if you dance without disrupting the floor it’s acceptable no matter what the move.
OK, then, so we agree that it's not the move
per se which is the problem.
The problem is it’s a show move and it’s meant to be danced big and that’s how it’s taught. How many people do you see doing them small? Really!!!!!
I see plenty of people doing them small; generally, the people who are already considerate of others and floorcraft. I see plenty of idiots throwing it in wherever, doing big moves that have no place for the situation...but they tend to be inconsiderate idiots regardless of what they're doing. Again, it's not the move, it's people whose discretion in these matters is lacking.
As for it being taught...I have seen plenty of moves taught that, while technically show moves (I suppose), can easily be adapted for a crowded social floor. Or that can be danced big and flashy for those occasions where there is more than enough room to spare and it doesn't matter if someone dances big. The problem is not the moves...it's the people.
Generally speaking, though, I see far more people doing them small and unobtrusive than making them disruptive. The disruptive ones are a few repeat offenders.
Ask yourself why would they teach show moves when their students can’t even comprehend walking or simple ochos? I watch week after week Tango instructors, some terrible and some the top dancers in the country all teaching the show moves to rank beginners. Go figure?
And I've been in workshops that were supposed to be limited to intermediate/advanced dancers, and have had rank beginners in there. Never mind that it's not fair to their partners in rotation, or flat out dangerous. (I almost got dropped one time. I'm a bit tetchy on this point.) Should the organizers have had the stones to throw them out for not being able to demonstrate mastery of basic concepts? Ideally...but we all know how well that goes.
Likewise, I've sat out from a group class because it was an "intermediate" class because I didn't figure I was ready for it as defined by the instructor. I appreciated that he established something of a minimum requirement. But as I sat on the sidelines and watched, I saw plenty of students who did not meet that minimum requirement...so what was the point, ultimately? What it came down to for me, is that I won't take a class from that teacher.
Unless you're going to establish a system where people have to "check out" of a certain level and present a cert before taking a given class, there is no way to police this. Not unless teachers want to start losing money. I'm sure plenty of students think they have mastered basic concepts just fine, which in fact they really have no clue how far they have to go. But just because some beginners take a class they probably shouldn't, and the possibility exists for them to use it without good judgment on the dance floor, is no reason to restrict the rest of us who would like the chance to add to the repertoire and explore new applications of traditional concepts.