Asking someone if they support violence is like asking if they support the coriolis effect. It's a fact of life, not just for humans but every living thing, that we have to deal with sometimes. It's a nonsensical question in most contexts.
Better to ask if someone supports self-defense against violence.
In this case, if they support self-defense against institutional violence.
It's not gatekeeping, none of the opinions shared here by Linus are categorically leftist. The person retweeting him is erroneously putting him into a box, or knows more about his full ideology than he's shared in the tweet.