I still don't see your point. It's bad that Betta splendens were selectively bred but dogs, horses, cows, chickens, cats, peaceful fish, reptiles, flowers, fruits, vegetables...... all of these are good? Its the same thing. Everything I mentioned has been selectively bred by humans to have the characteristics we want and get rid of the characteristics we don't.
Personally I don't want to see a colony of Betta splendens because to me they would not be the same fish. Just the way I wouldn't want a Doberman Pinscher who loves everyone he meets or a Labrador who doesn't want to swim.
Starting a new or hybridized species (although I'm generally not about hybridization) would be much better than trying to take a good thing and change it just because you don't like one aspect of it.
*Be smart.. Do your research!!*