Why not horns?

Perhaps your reality, not mine. I think your comment "The systems always could play loud, and usually did, could go deep in the bass and with a lot of volume, and threw big images. But to get those traits they often veered quite a bit away from truth in tonality." is a gross mis characterization of reality. As you may (or not, apparently) recall his reference systems were broken into categories: large, medium and small. While it is true that his no.1 reference speaker system was the IRS he championed many smaller ones like the Crosby Quads (and who can argue with the "truth in tonality" of those), smaller Thiels, Proacs and Sequerras to name just a couple. But, more importantly, I think you miss the point of the bigger picture. HP was TAS, and the adherence to strict standards of reviewing (flaws and all) and variety of opinion expressed by his chosen reviewers (and subsequent rebuttals) was something that was unparalleled. Sure he was a gear head; so what? That in no way detracts from his loftier contributions. He had a tremendous amount of influence and it is true that he (with a negative review) could cause great harm to a start-up, but on balance his positive contribution to the health of the industry was huge.

Funny, because I transitioned from a pair of Crosby Quads (which I still have) to my horn system back in 2006 or so, largely because I wanted the best of both worlds- the dynamics and vividness of the 'big system' together with the open, unboxed quality of the Quad (though i still think, at least in the midrange, the 57 is better than the 63, even as modified). I don't remember HP overtly bashing horns, perhaps he did. Or was it a sin of omission?

dc10audio is all horns!

Frogman, you are suffering from a bit of hero worship and unfortunately don't really know the real scenarios that played out. Neither do you know the sound there over those years, obviously.

Really? I don't think so; my heroes make music and sound not write about them. Here's what I do know: I can't remember a time that I bought a recording that he recommended, and then, when judging the sound of the recording on my system not being able to verify what he described. Operative word here is MUSIC. I am not aware of anyone else being so articulate and accurate (aargh!) in the way that he wrote about recorded music; and the passion with which he did so. That is good enough for me. Additionally, I can't think of a component that he spoke highly of and which I then owned (not many), or had extensive experience with, that I disagreed with his assessment of. The man has great ears.