Why? Ive seen carp, roach, tench and perch all kept in living room set ups. As a rule of thumb though, the bigger and better your kit, the happier and healthier your fish.
I wouldnt try eating them though as I was speaking to a fish keeper who has some really big tropical fish, he`s having problems trying to rehome and when I suggested knocking them on the head and feeding to the cat, he told me the nitrates build up in the flesh and make the fish inedible.
With all due respect, you cannot compare a brown trout to those fish mentioned. IMO.