EzekielRaiden
Follower of the Way
I think the issue is more that 3rd edition started with a hell of a lot more options than 2e did. Arguably orders of magnitude more. And it just went up from there. It might not have initially been as many options as you had with absolutely every 2e supplement, but it pretty quickly met and then surpassed that line. And, regardless of whether it was a lot of options in raw numbers, I'm pretty sure it felt like an enormous number of options to people who'd been used to the old-leather comfort of previous editions.I dunno, if you looked at the multiplicity of supplements for AD&D 2nd Edition, you could draw from a large number of them to create a truly broken character.
It really does seem to be that when people see new things, unfamiliar things, in an RPG ruleset, they seize up. They feel trapped, hemmed in by rules they don't understand and jargon that conceals rather than illuminates. And that may truly be the "benefit" of open playtesting: it does diddily-squat-all for, y'know, playtesting anything in a design sense, but it exposes people to the ideas and jargon before the game is out. That exposure softens the blow. It allows the players to skip over some of the early-discomfort-weirdness. Pair that with 5e's efforts (both active and passive, explicit, implicit, or tacit) to feel as "traditional" as possible (and, as most have noted, that meant doing things 3e's way, just less broken), and you may get a big reason for 5e's success that has literally nothing to do with the content of the rules whatsoever. It doubly eroded the usual opposition to new rules via a looooooong "get to know me!" period and styled itself incredibly closely to the still-pretty-popular 3rd edition.
(This may also go a long way toward explaining why it's not as popular among 4e fans, in addition to all the other well-known reasons, now that I think about it. Note the emphasis on "as" here; I have no idea what the statistics are, but my experience has shown that people who liked 4e at least had some meaningful beef with 5e even if they'd still play it.)