If companies are going to benefit from permissive licensed open source, they have obvious selection pressure towards that end for the code they create. I agree with you on the outcome; I'm not sure that I think it was startup culture that caused it, but rather any ecosystem where software was important and near ubiquitous would have evolved roughly the same way.

For my own hobby code, I don't see any practical benefit to GPL over MIT. I want my code to be reusable in as many cases as possible. I've seen the toxic treatment AGPL code gets (AFAICT, the main value of that license is to companies who offer dual licenses) and the wary treatment GPL v3 (or worse "v3 or later") code gets.