Yeah, apparently there's some kind of bad blood going on between Mentzer and EOTB, because the latter (in previous threads) accused the former of pussifying D&D and being a reason TSR went belly up (which is funny since Mentzer left when Gygax did), as well as other kinds of passive-aggressive needling. Instead of laughing off such an idiotic claim or mocking EOTB or just ignoring him, Mentzer demanded the star treatment and when it wasn't given (to DF's credit*), took his ball and went home -now for the third time. If it wasn't so funny, I'd feel sad for Mentzer's Norma Desmond-like fantasy that he's a big shot who should be treated better than the lowly serfs.
*DF has issues of its own, namely that members of the K&K Klan have, with the consent of the proprietor, more or less taken over moderation duties. So, while K&Kers are free to attack other posters, any kind of lively response is twisted into being a "personal attack" and met with bans and threats of same. Similarly, when a K&Ker starts getting owned in a discussion, the bans come out, threads get locked, etc.