I guess this was a bridge too far, and not the fact that his username is RAPEMAN, or the multitude of other edgy jokes on his credit pages. Take chapter 4 for instance, where he implies that all Muslims are literal insects trying to destroy every civilization they infiltrate. Guess that was A-OK for Mangadex's staff. Even chapter 7 has a reference to the events, but its still there.
Edit: Also, there sure is a lot of loli and rape porn for a site that exposes such fine morals.