Agreed- I regularly have customers come to me and state matter-of-factly that they will bring such and such fish to me at work when it out grows their tank, to which I bluntly say "no, you wont. If its too big for you, what makes you think its not too big for me?" I get the same shocked/puzzled look every time, which usually leads to informative conversations about why that fish is inappropriate in the first place.
Since I started doing most of the fish ordering at work, Ive made a concentrated effort not to bring in fish that will out grow the average home aquarists tank, with rare, specially requested, exceptions. No sharks, no morays, few large tangs, no xl triggers, no sweetlips or large groupers, etc. I think there needs to be greater awareness of the animal's well being and responsibility at All Levels of the hobby. Not to mention, there are a tremendous number of fish that are great for most any reefer- why insist on having one of just a handful of truly inappropriate animals?
The one time I put a risky animal in my personal reef tank (a juvenile Blue Face Angel), it took 4 hours of disassembling to get her back out of there when she decided to go ballistic on my softies. I no longer take risks like that (that's what the fish only is for). Any fish that goes into that tank is staying there for the rest of its life.