The RTS is yet another of the many, many examples of the very confusing situations presented to beginners by a typical large retail display of tropical fish. Although I assume there are exceptions (rare retailers watching out for the special needs of the beginner,) most displays include large numbers of fish that really need pretty special treatment. I once took stock of a large pet shop tropical display of tanks and decided that more than half the tanks were displaying fish that most of our experienced members would probably think were questionable for the beginner experience. In the case I was looking at, the entire right half of tanks (and more) were types that just wouldn't have been likely to either give a good beginner experience or, in more cases, just need extra attention to the volume, shape or other tweaks to the environment.
I guess the wild card when thinking about this is whether the beginner happens to seek out and find advice, as is happening in this thread. Beginners can, and do, set up large tanks sometimes and that carries the extra advantage of giving the aquarist more time to detect water chemistry changes, not to mention giving the fish more volume. But if we had the statistics, I'd bet that more often the subset of fish that need especially large water volumes or special lengths or depths just find themselves in too small a tank. Besides good advice for beginners, I'm not sure what else can be done other than perhaps extra tank labeling.
WD