It started as a free speech Twitter alternative aimed at republicans. But along with republicans and free speech activists they've attracted right-leaning extremists that were banned from Twitter for a plethora of good reasons. As a result of those users being left unmoderated, Gab gained a certain reputation.
Gab's apps weren't accepted to either app store, they were booted by several hosting companies, had to switch domain registrar and their stripe account was suspended. Switch to a Mastodon fork is a recent development.
Gab was a platform advocating "free speech" and as is the meme with those types of platforms these days, it was filled by people denying the holocaust and claiming all black people operate better as slaves. The list is not exhaustive, but you get the idea.
To my mind, no good-faith claim that such things do not need to be ostracised exists.
Them being on Twitter is bad, but being on their own platform is arguably worse.
I fully agree with this. It will end up being a self-fulfilling prophecy for those arguing against true freedom of speech. When you deplatform a viewpoint entirely, then the people with that viewpoint are going to coalesce onto a much smaller platform, which will end up being an echo chamber for the viewpoints that the rest of the world desires to quash. Then, it will end up becoming an argument to prevent such echo chambers from even forming in the first place, which would effectively make it impossible for smaller players to get an inroad, as they'll just be preemptively accused of being inherently alt-right.
These people don't understand that, when you centralize control over avenues of speech like that, then one day that centralized control can do a 180 and start banning any type of speech, and not just "harmful" or "problematic" speech.
It's literally the same type of tactic that China uses to suppress dissent, just on a different scale (and with a different culture behind it). It's so transparent, yet the prevailing "public narrative" is still highly supportive of deplatforming.
This argument is compelling on the surface, were it not that Europe has had laws against this kind of speech for a fairly long time now and it has made nothing worse. The place where it really is worse is the US, where even people who are not fascists seem to imagine that it is important to give them a "platform".
However, I don't anything about it. Maybe you can share.