I suppose uncritical support would be an indicator, maybe that's what you mean by "regardless", but Gruber has never been shy about stating very clearly and forcefully when he disagrees with or doesn't like something Apple is doing. Just recently with the Safari UI redesign for example, or the problems with some of the desktop cameras.
And Gruber's attention to the little details is unrivaled. What other reviewer is going to notice and call out Apple's keyboard for getting shiny over time because of the particular kind of plastic they use?
With Gruber, I do think he is honest. His strength is, that he can give a good view, what might have been the reasons for the design decisions Apple took - as any device is the consequence of design decisions. Of course, he also has a ton of experience in the Mac world, so he can very well compare to all the other Mac models.
Apple has become what it is today as the years have passed though. So the background around this guy has shifted. His writing and quality has remained the same, but you're right - it has become harder and harder to take him seriously. In part that is because he's defending positions which don't need defending anymore.
Gruber, though, gleefully repeats that "Apple says it's faster".
https://www.digitaltrends.com/computing/m2-macbook-air-revie...