I read TAS religiously from the late 1970's until around the time the world wide web emerged in the mid-1990's. I also read pretty much all of the other major audio-related publications of the time, and a number of the minor ones, representing pretty much all of the points on the spectrum of audiophile ideologies. I found that I could glean useful information from all of them.
As a technically oriented person I certainly had issues with a lot of what I read in TAS, especially when the writers hypothesized technical explanations for their sonic perceptions. However, based on my listening experiences during that period and those of my audiophile friends, I don't think it can be denied that the listening impressions reported by HP and many of his writers tended to be more consistently spot on than those in any other contemporaneous publication. Albeit with matters of degree perhaps being somewhat exaggerated at times.
Concerning Harry's considerable power and influence, it seems to me that ultimately its most significant effect was promulgation of his fundamental underlying philosophy, the use of the sound of acoustic instruments in a real performing space as the ultimate reference. And promulgation of that philosophy was sorely needed at the time, and all to the good, IMO.
If some folks followed his recommendations blindly, and if he had great influence (which he did), that is not his fault. My perception has been that the net result of that influence during the roughly 20 year period in question was more beneficial to the evolution of quality audio reproduction than that of any other audio reviewer or journalist.
And btw, I've found Parker's wine ratings and books to be useful as well.
Regards,
-- Al