I've kept just about every freshwater North American sportfish (including Spotted Gar, Chain Pickeral, and yes Bass), along with all kinds of tropical freshwater, and saltwater fish.... even an Octopus, a Stingray, Mudskippers, you name it ! If I haven't kept them at my own house, I've kept them in one of the tropical fish stores, or the fish farm that I worked at.
Bass make as good a pet, as any Oscar, Pacu, Koi, whatever. As far as fish go, Bass have tons of personality. They can be trained to eat just about anything. Mine ate strips of 98% fat free ham..... which was easy to aquire, and to store, but it was fun to feed him feeder goldfish, crawdads, worms, etc as well.
With proper tank cleaning techniques, the right equipment, and a tank which is properly balanced, keeping a bass should be fun, easy, and educational. The biggest problem I saw, over and over, when working in fish stores, was with people who didn't undersatand how 'cycling' a tank worked, and who therefore tried to just keep cleaning and cleaning to "force the water to be clear" causing themselves nothing but problems until they finally gave up.
This is true for any fish, but even more so with large fish, that eat a lot, and put off a lot of waste.
As for the legalities, let me put it this way, of course I can't recommend that you go transport a live gamefish to your house, and keep it as a pet...... However, I would bet that 95% of the F&G Biologists, and whole bunch of the other F&G workers, including Wardens, {and basically just about anyone else who has been into fish as much as I have, for their entire lives} have kept a bass or Bluegill as a pet themselves, at some point when growing up.
I agree with any of you who said, "A bass is just a fish" ......albeit, a very cool fish, which makes a great sport for one guy, a great dinner for the next, and a great pet for yet another :-)
Just my .09 cents,
Fish
PS, I wouldn't release a "sick fish" back into a lake..... But then I almost never had sick fish.