It should honestly come as no surprise considering Gab, much like Voat, is a website filled with some of the most vitriolic and racist garbage I've ever seen. No company wants to be associated with a walking PR disaster.
Most of the time however they're more than happy to take money from said places as long as people don't make it into a big PR problem.
I can see "some of the most vitriolic and racist garbage I've ever seen" on Twitter any day I want. Granted, I don't want to go on Twitter that often, but finding garbage there is not a problem. I mean, https://twitter.com/louisfarrakhan exists and this is the person who literally talks about "Satanic Jews". Why it isn't a walking PR disaster I wonder?
Historically, voat and gab were set up because its users disapproved of the moderation on reddit and twitter. That differentiates the cultures on voat and gab from their predecessors.
That is an extraordinarily charitable way to describe the genesis of Gab, which actually has roots in a YC batch (that its founder, Andrew Torba, was kicked out of).
Torba had an unrelated YC startup during the batch that was running during the 2016 election season. He was ejected from YC for harassing batch-mates; there's an HN thread about it you can find in the search bar. He started Gab at just about the same time as he was kicked out of YC.
Of course it exists everywhere in some measure (one can’t change the nature of humanity all that easily with just a website), but at least YouTube/Twitch/Facebook actually have some degree of value/utility. Voat et al appear to exist as little more than platforms for hateful bile that isn’t tolerated elsewhere.
Most of the time however they're more than happy to take money from said places as long as people don't make it into a big PR problem.