If an amp is not capable of going from clean to lead tone with just a twist of the volume knob, it does not come home with me. I personally do not get blackface clean amp plus dirt pedals thing. I have auditioned a lot of dirt pedals and they never feel or sound as good as even a well-designed solid-state amp like the Tech 21 Trademark 60. Heck, I only use the drive channel on that amp. The volume and tone knobs on a guitar are powerful tools.
My issue with the first part of the quote, meaning as it applies too me, is this. Why should I settle for anything less than the type and EQ of cleans I want? Why should I settle for anything less than exactly the gain tones I want? A two channel amp gives me the ability to choose an amp with the cleans I want and the gain tones I want. Even on an amp as great as the Archon, I can get MANY different tones from each channel, but you must change the knobs to get them. I can adjust the level of gain on each. Adjust the EQ of each, etc. No amp could give me the cleans I want and the gains I want AND the ability to change both, when the only way to get from one to the other, is the volume knob.
Second, if I found one amp that really cleaned up great and worked perfectly for this thing with one guitar, as soon as I change guitars, the quest starts all over again. When I switch from the NF3 to the C24, I know I need to turn presence and treble up, mids and bass down to get similar tones to what I just had. I can control the degree of each on each channel.
And, PRS guitars are far better than most at cleaning up with the guitar volume. They know the formula to make this work and it's something PRS guitars have always been great at. But what about a strat? I've never had a strat that didn't lose sparkle when rolling off the volume. With a two channel amp, that's an easy fix.
OD/Distortion pedals only enhance everything I've said above. If I want a dumble type tone, or even just a smooth fat OD while my amps OD channel is dialed to higher gain tones, I just put the right pedal in front of the clean channel.
I'd love to find a amp and guitar that did this well. But at best it would be a compromise from what I have now. And IMO, ONLY with pedals could I even think about it. But while I'd gladly have an amp or two that did that, like a HX/DA or Blistertone or MDT, I would not be happy with that as my only amp, or with all my amps being like that. I play anything from clean to metal and need to cover all those tones.
I've also had a Trademark 10 and played a 30. While "good" I'd never even think about comparing their tone to some of my good tube amps with pedals. I have some pedals that with my C50 or Archon or 2 channel H easily sounded better than many good tube amps. And it's not an uneducated or untrained ear, it's just that there are some really good pedals out there that with a great clean channel sound VERY good.
Lastly, I've never been able to do any real nice cleans to nice gains with a volume knob, unless the amp was pretty loud and the tubes were working. That's not always easy or sometimes doable in many circumstances now days. I can't take a 30 watt HX/DA to most any place I play and turn it up half way to get great clean and gain tones.
So yeah, I'd have one single channel amp to do this with, but it could never be my "only" setup or all my amps be this type.