what attacks are you specifically referring to here, other than kicking them off the site?
The admins always had some new rules and some specific ways they had to be enforced, and were always happy to heap ever-increasing punishments on the subreddits capriciously
Oh, you can't say "Retard" any more, if we find any more examples of this prohibited hate speech your subreddit is going to be actioned against. Also we banned half of your most active moderators for wrongthink. We'll continue banning moderators and levying punishments until the situation is rectified.
I don't think there is a neutral interpretation better than "the_donald was a lot of trouble for reddit as a business and social network, because they caused hostility, even by their existence, and it's not reddit's business to make humans less tribal, so why continue supporting them? Especially after they were clearly brigaiding and manipulating front page content. This front page manipulation was different from what the reddit owners wanted to be on the front page, which for the most part is benign and fun stuff that's easy to monetize."