Commissario
Most people's living rooms also aren't particularly great for 5.1 etc, and most people don't watch with a 5.1 setup most of the time.Not me saying it. Lots of sound mixers where posting about it etc. Dolby is ultimately in the licencing business.
I can understand a certified by Dolby Cinema done by their own techs, of which a search says theirs only 5 cinemas in the UK that have that certification lol. Everything else is a third party that dolby sold the license to. But the likelyhood of 99% of people's livings rooms having the right walls ceilings etc is hard to believe.
Basically Atmos is from memory backwards compatible, but if you've got the equipment it does make a big difference as from memory it's intended to do sound from "above" and "below" not just to the front and back of you.