The basic issue comes down to being consistent. If one assembles a home theater system without taking heat loading (and noise) into consideration or you may learn (the hard way) to be a bit more discriminating the next time around. If fact that is what life is all about? Advertisers love inexperienced consumers because they are so malleable.
With the American standard-of-living steadily going downhill (read smaller homes and rooms), it's wise to understand the system you are building before purchase or assembly.
For a bedroom TV, do you want to put a large heat generator and try to sleep when the room has become too hot? For myself, personal comfort is more important than the cost. I mean its 105 outside and the sun has baked the walls and roof. The air conditioner has a hard enough time as is...
Now let's take the A/V controller, amplifier(8+ channels), big screen TV and disc player plus cable box, modem and power conditioner.
Some brands of A/V controllers/receivers get very hot, with Onkyo coming to mind. They can uncomfortable to touch. Or Krell class A amplifiers.
Instead of too much heat making the room become uncomfortable as you watch the movie, why not make alternative choices?
I'd buy the much cooler running Denon over Onyko as they are superior in every way, including sound quality, comfort and power bills.
The fact is a system which make people uncomfortable will be used less often, except if you live in Alaska. Trust me on this one.