Didn’t Gygax owe a little thanks to WotC and new D&D? Don’t we all owe them a little thanks for bringing the man back on stage for us?
Some will say that he'd not drifted into obscurity, and while he may still have had some venues of communication, I don't think I can accept the notion that his exposure was of the same size and scope as in his heyday with TSR.
Consider that WotC brought about 3e. 3e brought about EN World. EN World had the Gygax Q&A threads. Does anyone have a strong argument that this did not bring some Gygaxian wisdom to at least hundreds, and possibly thousands or tens of thousands that would not have otherwise heard it?
So, yes, a nod of thanks would be appropriate. And I think he gave that in his dealings with Peter Adkison.
So someone who is not a fan of game X means that they are of low character now assuming such "circumstances" were correct to begin with?
No. But Gary was more than just "not a fan" - he was a seminal influence, and still active as a professional. We should expect him to behave in a professional manner. And there's nothing wrong with asking if maybe he occasionally got a little more crotchety than was appropriate for his position.