the real world means no dedicated listening room, probably the majority here....
A lot of people using room treatments have no clue as to where to even place them, rendering them useless or even detrimental.
Many people -- not everyone -- have a room for a couch and TV. They just don't use it for audio. They could. They don't. So, there's that.
A lot of people using room treatments could figure out where to place them if they tried, just a tiny bit.
Seriously, improving sound does not require an elaborate listening room or a Ph.D. in acoustics. It's a hobby which requires a little knowledge and effort. Like fishing. Like golf. Give me a break -- it's not that hard. If one doesn't want to try, then that's their call. But it's not the fault of the hobby.