I dunno, I think a lot of people complaining about stuff like that are just trying to find a reason to prefer their amps over an AxeFX, like not jumping on the modeler train is some kind of badge of honor. More than half the guitarists I’ve played with or talked to have never paid attention to their tone under a microscope or in studio monitors. Perfect example is a few years back we were tracking guitars for a band I was in, my buddy/guitar player was using a Dual Rec into a Recto 4x12, gets it all set up in the room and I put a mic on it. Sounds like a pile of ass coming through the studio monitors no matter where we put the mic, too much bass and distortion. After 45 minutes of letting him tweak the amp himself I told him to give me a shot at it. Went in and turned some knobs, came back in and had him track a couple sections, listen back and it sounds perfect. We take a break after a while and he goes back into the room with his amp, plays some guitar and says “It sounds like shit in here! I don’t want this getting recorded!”
GreatGreen note: tl;dr - sounds great when recorded but like crap in the room.
I have experienced this exact phenomenon multiple times when I used to help my buddy record bands. Some of them would come in with stuff like 5150s or Rectos and a Mesa 4x12 cab, so we'd put a 57 and one or two more mics on it and get to work.
I was the one dialing it in. The head was in the recording room so I basically had to walk back and fourth between the mixing room and the recording room. Tweak, walk, listen, repeat.
I remember being in the listening room finally having dialed in the biggest, meanest, clearest, most ferocious tone coming from the monitors, but actually sitting in the recording space with the amp, you'd think you were playing through a flubby AM radio. No bass, no treble, no definition, just endless thin, muddy mids. I had to reassure the guitar player multiple times. "Yep, sounds like total shit in here. It sounds incredible through the monitors though." He didn't believe me until he heard the stems played back to him.
I think most people have just never tried to record a physical guitar cab with a real mic. They simply don't know how different in-the-room listening and through-monitors listening are from each other, and how different you have to approach dialing an amp in to get a good in-the-room tone vs a tone that will record well, or even what a physical amp and cab that will sound good recorded
actually sounds like when you're standing in front of it.
Most people assume "if you mic an amp well, it should sound the same through the monitors as it does to me personally in the room" and this simply could not be further from the truth in my experience.
I'd also bet that if most people could travel back in time and be in the same room as their favorite sounding recorded guitar tones from their favorite records, they'd probably think it actually sounded horrible in the recording room itself, or at the very least, not even remotely close to what the recording actually sounds like.