SA was my first paywall for content, my first micro-transaction (forum avatars, titles, etc.). There were elements of reputation and social networking. I don't know how it all went so wrong.
I'm wistfully in what-could-have-been mode since the products I use these days (Reddit, Twitter) are a poor approximation for what SA was at its height.
There's a joke about one of these events.
One year the SomethingAwful.com forum moderators got annoyed at the annoying anime fans, so they banished them. 4chan was born, yadda yadda, Donald Trump is elected president.
And, I don't think you can blame SA for 4chan, nor 4chan for trump. Both trump and 4chan meet a demand, and that demand would have been filled, one way or another.
Would there still be something that fits roughly the same niche as 4chan, if 4chan didn't exist? Most likely yes. But it wouldn't be anything like the 4chan we know today.
Permabans are not common.