Totally disagree! If anything, I find that the differences between guitars and pickups is more pronounced than I'm used to with a regular amp. I guess if all one plays is high-gain sounds, then you probably have a point, but if one mixes and matches different profiles of different amps in a performance, one has to be quite discerning when changing guitars, too.
At least that's my experience.
Cheers,
Sam
Exactly my sentiments.