Tom,
I'm not trying to convince them that they are not having fun, I've just offered up some evidence that supports my belief that amplifiers do not colour sound. It's a very simple electronic process of amplifying what the source sends. Having said that, you'll notice that my music system consists of a tube amp driving a pair of M3s. The purchase was partially nostalgic, but mostly done because the music just seems to sound better while sipping on a 15 year old Macallan, room lighting off, and stairing at the pretty orange glow of the tubes. I A/B'd the tube amp vs a little NAD amplifier and found there was no difference in sound at normal listening levels, in my home, with my speakers. My Engineering mind, however, conceded that I liked the 'emotion' of using the tube amp, so I spent a few extra hundred dollars on it, even thought I know the sound is no better then a much cheaper solid state amp.