Thank you for sharing this. I had been feeling similarly for awhile but couldn't really boil down why. His blog went from must-read to unreadable. I wish I could remember which post threw it over the top for me but I had a visceral reaction at one point best summed up as Really?
On the Gruber thing, he has written saying that Gruber is his ideal reader, so yo aren't far off the mark.
I think that as his traffic, profile and software sales have grown, he has lost his humility, which is a bad thing for writing.