It's a convenient excuse. The reality is that the admins are continually clamping down on subreddits they don't like, without any justification or consistency.

For example, one is left to wonder why /r/drama was forced to shut down because the admins considered them a nuisance, yet left-leaning subreddits engaging in vote-brigading and other equally disruptive behaviour are still around.

I'd be remiss to claim that it's purely a left vs. right thing. But if the Aimee Challenor debacle was any indication, they have a clear list of people they like and people they don't like. And if they don't like you, for whatever reason, they eject you from the platform without any recourse.