It's usually a "It's not handwired, therefore it's crap" mentality, often from people who own e.g vintage Fenders and Marshalls, or other relatively simple amps from a specific era. The claim is often not rooted in reality and newer amps are not necessarily better or worse, just different.
I think that view is overly reductionist. There are tons of valid reasons that have to do with real experiences that have nothing to do with “It's not handwired, therefore it's crap”. Also, I think a lot of people who said that said it because they knew something wasn’t as good as it used to be, but they didn’t know exactly why so they decided it must be the hand wiring.
The problem is, anytime there is an introduction of something new it takes a while to perfect the new technology. Early iterations aren’t as good, and therefore early adopters turn on it as “not as good” and hold that view forever.
Early Solid State amps weren’t very good so people adopted the belief that SS sucks and still hold onto it even though new SS amps can be great.
Early PCB amps weren’t as reliable because they were made to cut costs and the quality of the boards tended to be cheap. So people adopted the belief that PCB isn’t as good and still hold onto it even though newer PCB amps can be every bit as good and reliable.
I believe the same thing happened with highly complex amps. I remember playing Mesa amps from the late ‘90s and thinking they sounded terrible. It seemed to me like the more complicated they made them the worse they seemed to sound. They were dull, muffled, uninspiring sounding amps to me. And I assumed it was because of the complexity of the circuit.
I still think there is something to be said for a simple circuit, but the first time I played a Mark V it made me realize I was wrong about complex amps. That amp sounded fantastic, 1,000x better than anything I’d heard from a Mesa in the last 20 years.
The fact is, sometimes newer amps
are worse. But also sometimes they are better. Being new or old has very little to do with it.
I’ve never seen a situation where cost cutting measures from a company result in a better sounding more dependable product though. Typically it’s the opposite