Nellisir
Hero
... there's good reason to hope that even if the tribalism doesn't disappear, which it won't completely ever do, that it won't be nearly as big of a problem this time around.
As someone who's found himself ostensibly "in" the OSR, I think the tribalism is a lot more sound and fury than anything else, but that might also depend on which branch of the OSR you're in. I write game material for Swords & Wizardry, which is simultaneously the simplest and the most progressive of the better known retroclones. I have no animosity towards WotC or D&D; I just burned out on all the numbers. I like Pathfinder, but same problem. I really like the look of 5e, but at this point it's so amazingly easy to write stuff for S&W that I think I'll probably play 5e and write S&W.
How well the two interact is something I'm obviously curious about, but since I think 5e won't use the OGL, it's not a primary concern of mine.