Good topic by the OP and an unusually civil discussion! Thanks to all of you for that I agree with the OP on many points, but let me add a few on what I've found matters most (at least, to me)...
1. Recording quality (regardless of format) is essential. A poor recording will never sound as well as a good one, in any system, in any room. (Please copy, Michael Greene...)
2. Speakers do the most to create the 'sound' of your system. But synergy of spkrs. and amp is CRUCIAL for optimum performance.
3. A good room makes a huge difference. The less tuning or DSP necessary, the better. But if you have problems, DO tune or use DSP to improve the room acoustics. Even in the best room, bad spkr. placement will kill the sound, so start with that.
4. The more revealing your system is (and your ears are), the more cables make a difference. And yes, some cables do seem to cost ridiculous amounts of cash for 'wires'. But my experience is that once you've built a nice system, the right interconnects, A/C cords and (to a lesser extent) spkr. cables can take it from 'nice' to 'extraordinary'. Is that sonic improvement - and the emotional payoff when you listen - worth paying more than you THINK they should cost? That's YOUR call...
5. Price is not always commensurate with quality... but (sigh) it often is. I've always sought out 'bargain' components (and cables) that provide great sound, and often found them. (My spkrs. and amp both perform FAR above their pay-grade.) Other times, you just have to pay to get the best stuff. But remember that great sound CAN be had at a bargain, and that throwing a bunch of $$ into your gear w/out considering system synergy can be an enormous waste.
I hope this is helpful. Thanks for reading, and...
HAPPY LISTENING!