How important is the speaker/room interface?

In my years in this hobby, I've come to believe the speaker/room interface is one of the most important elements we face in building a satisfying audio system. And while it seems there is a growing realization of this point (emphasis on speaker placement and room design), I don't believe it yet receives the attention it deserves. For example, some folks who have never addressed the sonics of their listening rooms may spend weeks and significant money trying out different wires when a different speaker system and/or room treatments could provide far greater sonic improvements.

I have three friends who have the same make/model speaker as I own. I've listened to each of them with the same or similar amps, yet the sonic results are significantly different. The primary difference is the rooms -- volume, shape, construction, decoration, etc. So while I've made adjustments in my own speaker/room to improve it to a reasonable extent, I know my speakers could sound better in a more optimized room based on this experience. No change of sources, electronics, wires, tweaks, etc. could effect as much difference.

I'm thinking about this now since I just read the HFN history in "Sound Bites" by Kessler and Harris. In a 1994 interview by Ken Kessler with Peter Walker, Walker is ask what he believes still needs to be addressed in audio. His first response is the relationship of the speaker and room.

So, any thoughts as to why the speaker/room interface is not more universally considered the top priority in building a system?