Hello warnerwh,
I think you somewhat answered your own question. I don't think that most people understand what power/current capability is required for most high-end speakers. Two speakers with the same ohm/power rating on paper may act totally different in the real world.
Due to great marketing by most of the larger mass market and car audio amp manufactureres, a very large majority of folks (including some audiophiles) still associate power/watts with how well the amp will sound and "control" a speaker. Most peolpe just don't realize that power supply, architecture, and output configuration play a much larger role than advertised watts. All too many times I have seen someone post a review saying something like "I tried brand X and brand Y 200W amps with speaker Z and thought brand X sounded more open, musical, etc." and then have someone come back and say "Your a tin-eared idiot. I tried those two amps with speaker V and you are totally wrong. Brand Y amp is better". When I look at the specs I find that brand X has a 2kVA power supply, brand Y has a .3kVA power supply, speaker Z is a planar that is 82 dB efficient and goes down to 2 ohms and speaker V is a 106 dB efficient horn that never goes below 8 ohms.
The synergy thing as described by aaird is also extremely important. The old Acurus amps were notorious for being bright sounding. Put them on a speaker with a bright aluminum dome tweater and you felt like someone was drilling a hole in your head. However, they did a great job in bringing dull sounding speaker to life.
I agree with your statement that the room and cables/interconnects can have a huge difference on the sound. However, it would be extremely difficult to use a dull sounding interconnect to tame a bright amp mated to a bright speaker without severely affecting the music in a bad way.
Having at least a somewhat good idea that a speaker/amp combo can be made to sound good in someone elses environment at least helps most people get one step closer to a good system (i.e., if I know that something sounds great at your house and the exact same system sounds poor at my house I now have a much small list of possible things to fix: power, room treatment, or speaker positioning) If a person doesn't know that an amp/speaker combo sounds good in at least one other environment, then doubt and frustration will set in very quickly if the system initially sounds bad.
Just a few random thought.
Julian
www.sedonaskysound.com