I (for one) am glad Monte left.
I recognize and respect his style, and his creativity, definitely. I just rarely agreed or appreciated his actual design work (from what I could glean from his 3e and Malhavoc days).
His L&L articles always, always, left me feeling sick to my stomach. His undisguised revulsion of 4e and of game mechanics that I appreciated about D&D was turning me off to the future of the game like nothing else. His leaving revitalized my interest, and I hope it goes in a more positive direction than what he conveyed.
I'm glad he was only on for a few months. He wasn't a part of D&D Next when design began, and he wasn't a part of it for long enough to make a huge impact (I hope).