You posted a very long piece and yet again elected to avoid providing a single reason why anyone not playing 4E would do so.
Because the 'perfect storm' theory does not depend on anyone doing so.
But, if you want reasons people might have for playing a game that's not exactly your favorite: because your friends are, because you can't find enough people to play your first choice, because you're bored with the old game for want of any new stuff coming out for it, and, of course, because you finally set aside your confirmation bias and gave it a fair shot.
But, seriously, I can't prove a negative, it's up to you to prove your alternative hypothesis: if you have the data to show that 4e was played by vastly fewer folks than another edition, or even that it's revenue dropped off much more rapidly than is typical of supplements vs core books, and that such was due solely to the content of the game, then by all means, post it.
Otherwise, you're working with the same facts I am: that 4e was discontinued early in spite of selling well initially like every other new ed, that Pathfinder pulled ahead after 4e releases slowed to a crawl with Essentials, that an insider revealed 4e was pitched as able to deliver outlandish MMO-like revenue, that 3pps rejected the GSL in favor of the OGL, and that DDI development was derailed by the death of the developer.
Frankly, even /if/ there had been no OGL and hold-outs had (improbably) unanimously relented before 2010, the revenue difference wouldn't have been enough to meet the 'core brand' targets and they'd still have had to downgrade to Essentials. There'd've just been no Pathfinder to pull ahead of it's abysmal sales.