I think that's probably it, or at the very least part of it. TD has been a well-trafficed subreddit for a long time, and that means ad revenue. Around the time

I think that's probably it, or at the very least part of it. TD has been a well-trafficed subreddit for a long time, and that means ad revenue. Around the time of the comment-editing fiasco I remember a couple of other subreddits' mods saying the admins were quite friendly to the TD mods on the Reddit mod discourse. I wouldn't be surprised, considering the behavior they constantly got away with.