Nonsense...especially with single ended amps. If clarity and improved design for clarity is to be questioned that's just silly, as well as SS amps that, as Nelson Pass says "sound more like tubes" in a good way. It's the harmonic rules you just can't break easily, although Nelson tries successfully to do just that. Read why he likes the transistors in his SIT stuff. Also many, many modern (Gold Lion KT77s anybody?) tubes sound great, just as old tubes sometimes don't. I do get that great tube amps can be expensive as my Dennis Had SEP was 1200 bucks! (it was 4 months old...so it WAS used) And my Freya...don't even ask...I've got nearly 2 grand in just those two things...wow! Note these are both very well made and seemingly noiseless. Also, many may not realize there's a very large market for "reissued" tube guitar amps (nobody reissues old hifi tube amps, do they?) of all sorts trying to exactly replicate circuits from 50s Fenders and old Vox amps, etc. These amps are generally great sounding things, and I've owned both old and newer single ended and push pull tube guitar amps and either sound amazing.
Why don’t tube amps sound like tubes anymore?
When I hear the latest tube amps I’m more reminded of what a solid state amp sounds like than what I remember a tube amp once sounded like. I say that, with most tube amps I hear today, but not all. Gone seems to be the lush tones, warm glow and natural harmonics I used to hear. What I hear is more of a thoroughbred, faster, sharper sound when I listen to a modern tube design today. Then why use tubes?