I hear that. And agree that historical context is valuable and can better help us understand both sides.
Basically, i would argue that the F2P community succeeded both by having warm bodies ( this point isn't wrong ) but also by consequence of having so many new players, members of the community actively engaged in making this place fun for the F2P/Vets. Twinking has had how many interactions? How many pservers tried to offer a twinking experience only to die weeks later? Making a twinking community thrive isn't easy. And ours did.
So, many of us are protective of that, some overly so. And we don't engage with 29s, because the very few experiences we shared with them weren't good ones. Like Chops said, none of this happens in a vaccuum.
I will say this: People argue that F2P/Vets rolled to steamroll levelers, but from my experience, ever since Cataclysm, as a f2p, what really steamrolled brackets weren't F2P specifically, but Hunters. Always Hunters. When the bracket had a 6s CD Explosive Shot, what was really destroying the game were leveling Heirloomed Hunters and F2P heirloom hunters. When vets came, Vet Hunters were added to the equation. Sometimes, we got a more expanded FOTM, with Priests, Mages and sometimes, rarely, Druids FCing. But Hunters were the big scourge on the bracket, and what really made the bgs look like a scene from STALKER 3.
I'm sure a lot of F2Ps have the same Vietnam flashbacks i have of Worgen Hunters darkflighting in the mid of WSG and 1.1k Explosive Shots flying in our direction with 4s cd Conc Shots. Next to that, 29s aren't really anything to write home about. That doesn't mean i'll put myself through that suffering again, tho. What mr. Glancealot seems to be...*ahem* glancing, is that it doesn't matter how good his own perception of the game seems to be, for a lot of us, we will focus on a different aspect of the game ( PVE ) because it has less frustration and 20s are not playing F2P because we wanna be frustrated. There's a difference between having fun with the F2P ruleset, and actively try to destroy mountains while using a toyhammer.
29s need to understand this once and for all: When they says "adapt!", we already have. We have adapted to facets of the game that doesn't involve 29s. And when Blizzard force us to play with 29s, we will simply play something else in the game that doesn't involve 29s. We have adapted. 29s aren't part of our community, and i don't think they will ever be.