I would completely agree with you that they are not for the average aquarists who has a 50-75 gallon tank. Also, I am not considering putting these in a tank nor am I an average aquarist. I wouldn't intend to harvest these probably until about 25-30 inches long. I just relocated a 20 inch plus Oscar, and I find the larger fish are easier to work with. Example...Tilapia under about 3" are rather irritating as they constantly get caught in intakes, skimmers, jumping, birds eat em, etc. However the 12"+ are completly the opposite. I don't have the same problems with them jumping, though not sure why on that. They just don't. No problems with plumbing, birds don't eat them. Raccoons don't even mess with them at that size. And I can catch them on rod and reel when I want to eat one.
A little attention to detail and these could be viable.....for me. They are not for everyone.