I'd call it a tie between your comment and people who run 5.1 (or stereo) but refuse to use an automated EQ system (Audyssey, Direc, Trinnov, etc.) or manual EQ with a measurement system to address room issues. Or who plop a subwoofer down where it's convenient rather than where it performs best in that particular room/listening position(s). Completely agree that the room is the challenge, not the actual gear. It's amazing how much cash people will throw at hardware for a problem that isn't solvable with money unless you're hiring someone to help with room acoustics. Why people will spend thousands of dollars on gear but not a few hundred hiring someone to help with EQ/room correction remains a mystery to me.