Sadly, that's always been how a lot of folks set up their loudspeakers.This is certainly true, but the biggest part of that is that it is inconvenient to walk around the speakers that are in the middle of the room, or something like that. Perfect position may not always be the livable-with one. There comes a trade-off. I am sure that modest systems may outperform more expensive ones when everything is aligned well, but I would expect that, if both are placed where they are allowed to be placed, expensive ones will still be better. Of course, I have no examples to provide, but simply have that feeling based on my own very limited experience. Strangely so, in my own room, speakers really did not have that much difference when moved away from the walls and the trade-off was clearly on the side of "closer to the wall".
I wonder how many people who read these threads (not only this one) have an actual dedicated listening room. It must be a good number. Putting your music reproduction system in the living room may not allow for perfect positioning and tweaking/tuning, but adds the benefit of having it close to ears. That may be good enough of a proposition to some. If I am correct that more expensive system under the same circumstances will still outperform more expensive one, in some areas it may end up being cheaper investing more in equipment than in another room. A person just has to accept that the system is not playing to the full potential which, I am aware of that, may drive many people who visit Audiogon up the wall.
Along the lines of speaker positioning, some speaker manufacturers, not the shabbiest ones at that, proudly display speakers on their websites right next to the wall or really close to it. There are even those placed right in front of the glass wall. Check Dynaudio and Dali websites for such examples.