To be entirely honest, I think you're over-representing things quite a bit. I just spent a week at GDC and here's the sum total of Gamergate-related stuff that I experienced:
(And for some reason I kept smelling chocolate donuts at that talk, but I'm guessing that wasn't related to Schafer)
Yes, there's a bunch of really ridiculous talks, as listed in another thread in this subreddit. But there's always been ridiculous talks, and I'm fine with those ridiculous talks existing. Doesn't mean I have to go to them.
And just for comparison, you know Rami Ismail? He's an outspoken critic of GamerGate and seems to lean pretty heavy towards the SJW side of things. Well, he gave a microtalk on how his native language was treated in games. The talk was pretty good! (Unlike how his language was treated, ho ho.) And he didn't bring up GamerGate at all - it just wasn't relevant to the talk. Even though I don't agree with his personal politics, the dude got an Excellent rating from me because his talk was very worth going to. And I don't give out too many Excellents, I'd say maaaaybe one out of ten.
Don't get me wrong, I would love for people to build their own institutions, I'm not a big fan of the IGDA and I feel somewhat dirty giving money to GDC. But GDC is still a damn fine convention, it's still by far the best game development convention there is, and with the single exception of Tim Schafer, I never felt like the SJW/Anti-GamerGate thing was being rammed down my throat . . . or, hell, even mentioned.
So if you want to build your own game convention, (1) go for it, I'm all for it, but (2) recognize that even the most GamerGate-affiliated developers largely consider GDC to be a worthwhile convention, and you're going to have a hell of a struggle ahead of you to beat that.