Any of you guys ever fish at a pay lake or hunt at a pheasant preserve?
Its much the same - a large area with mostly contained species and a certain amount of trophy size available.
That doesn't mean every person will catch a fish or take home a trophy, but you are paying for the better chance to.

Conversely, I would never fish in an aquarium under any circumstance.

But the fact is, there is a market and a reason for high fence / exotics the same as a pay lake. I can't afford a high fence hunt so I have never been, probably never will, but it is good to know the option is out there.