I would use the word "Shrill" but maybe he's the creepy stalker that Nikon can't quite shake off and have taken a restraining order out against. He does seem to be rather single minded and more than a little obsessed with the brand, IMO.
From when I have read anything on Thom Hogan's site I get the impression of someone who has been passionate about Nikon for many years, and has tried to help them over the years when he may have had more direct links with Nikon. That no longer seems to be the case.
He makes part of his income from writing user guides for various Nikon DSLR's. Having read his guide for the D300 it explains how every aspect of the camera worked and then gave the reasons for using certain settings. It was excellent.
So he has a lot of experience of Nikon cameras, so when he reviews something he has a wealth of knowledge to call on. It will be very interesting to see any reviews of his for the new Nikon Z cameras and Z mount lenses and he seems to give impartial reviews imho.
He has also been following the camera market for decades, and so has access to information and data most people don't, or at least may be hard to find, if they knew what to look for in the first place, and so has insights most may not see.
Whilst he has been known for Nikon cameras he uses other brands as well, and indeed has part of his site is for mirrorless cameras, Sans Mirror. I enjoy most of the articles on his site, I don't always agree with what he says, but then whenever does that happen anywhere.
It is up to others decide what they think of what he does, once they have visited his site and read an article or two. Anyone criticising will be doing so from the experience of having visited his site though won't they.