....Also, I know there are a bunch of Pro-Audio amps out there that fit the bill, but most would agree that they wouldn't be satisfied with them for hi-fi use. The Carver is an exception as it is quite good due to the Tripath implementation.
Certainly, the Tripath implementation offers substantial potential, as do most of the standard A/B transistor topologies, Bailey, Symmettrical, etc....
Rather, the reasons are largely economic and marketing related.
Post hoc, ergo propter hoc.