Happened to me, the mod did not like the fact that I had engaged with a sub that he does not politically agree on, It was a university centric sub that I got banned from. Could never take that site seriously, ever.

I've seen this in just about every online space for 40 years now, but it is particularly bad there. I was deeply involved in several subreddits up until about '09-'10 and it slowly dawned on me just how far off the reservation the average mod was. I didn't even have any moderation issues personally, just from seeing it happen to others and the way they would approach rules and their day-to-day.

I quit the site entirely and have not looked back, but as an outsider everything I still hear about reddit moderation doesn't make my impression any more favorable. Quite the opposite.