I've been a fairly recent Emacs user, a year and half I suppose. I've found Xah really helpful in some cases when I was starting with Emacs. He tries to start online discussions, writes some tutorials in his blog, even starts G+ hangouts where he helps random people, and all this voluntarily.

I have no idea what discussions he has trolled or what controversies he was involved in. But there is a humble volunteer part of him I appreciate (like this HN item), and I believe in this way he adds some real value to the community.