I too at one time thought that if everyone could just see the beauty in Native fishes they would be instantly popular, here in the Southeastern US a great many aquarium plants were collected from the wild in the "good old days". Plants like banana plants, cape fear spatterdock, vallisneria, elodea, and many more all originated in the wilds of the US southeast. I have bred fish like black banded sunfish, blue spotted sunfish, redfin pickerel to name a few. A great many species of North American native fish from Dace to shiners, silversides, darters, pygmy sunfish, some gamefish, and many oddballs like sirens, mudpuppies, even a small species of sturgeon. This list is by no means complete and more than enough species of colorful of odd fish exist here to almost make tropical fish unnecessary. many of them do well at tropical temps, only needing a seasonal cool down to breed.
The truth of it is that many state and federal laws discourage the keeping of natives if not outlawing them completely but the reason we seldom see natives in pet stores is that the tropical fish trade actively discourages the keeping of natives for no other reason that they don't want us to keep anything we could potentially go out and catch for free. Promoting tropicals and discouraging natives is simply good business. I have been keeping natives and tropical together for 60 years or more, going out and catching your own aquarium fish is very satisfying and a fun way to experience the out of doors.
Breeding natives can be done with varying amounts of ease and the breeding habits of native run the gauntlet of behaviors from live bearers to fish that take care of their young in various ways. For anyone who is interested the North American Native Fishes Association
is a great place to start to obtain knowledge and skills to catch, keep, and even breed native fishes.