If you don't want to see any posts from any bots, the current easiest way is to use the web to go to your account settings and turn off the thing that says "show bots".

I don't disagree that it would be a nice addition, but that's what we can do in the meantime. Unless you want to just block each of them like they are a normal user, I guess. I find value in some of the bots, so I allow showing bots and just block the ones I don't like.