Twitch

Gamergate

This is how you know that these people have no clue what they're talking about and no interesting in finding out.

I've never seen a Gamergater express an overall positive opinion about Twitch. Most seem to be critical of it for one reason or another, whether it's the fact that it's owned by Bezos's Amazon, its use to sell borderline softcore porn and fake virtual relationships to minors, the administrators and moderators showing bias in moderation, or the bans on certain games.

As to why someone might livestream a criminal act on Twitch, it's probably because the platform is pretty much synonymous with livestreaming and there really aren't that many major players in the market.