What makes you build a system around an amplifier?

Last night I attended a local audio event and auditioned a pair of fairly expensive speakers from a well-respected manufacturer, which sounded really "grainy" and not at all pleasing to my ears.
So......I think I'd most agree with those who would select the speakers and work back from them.

I don't think I could ever bring myself to buy speakers based on an amp I owned. A big part of that is that I find it vastly easier to tailor an amp to a pair of speakers. Speakers prefer something between an ideal current source and an ideal voltage source with something between no damping factor and a massive damping factor. If you get the balance of those things right you're going to have an amp that drives a pair of speakers very well, but possible only one pair or a very small number of pairs. Since I'm not afraid to build an amp, I buy the speakers with the best specs and sound I can and then carefully evaluate the most suitable amp designs I can find and build accordingly. I think my modified F5 clone is probably as close as I'm going to get to a perfect match with my Focals. 

ejr1953---Are you sure the speakers weren't merely reproducing the grainy sound of the amplifier driving them? I have found "grain" to be more a product of electronics than speakers.

Amps are personal (in my opinion)  and I think it is perfectly fine to build a system around one.  Sure preamps and speakers are very important but an amp is the soul of the system.  Of course so are fuses, power cords and isolation lol ;)

I look at a audio system as just that a system its the sum of its parts. If you want a certain amplifier type the obvious answer is to select matching loudspeakers if you have a type of loudspeaker that you enjoy you match the amplifier design to it.