Yeah that's one of the reasons I don't breed, or if I do I usually keep a large portion of the fish I've bred.
We all condemn ignorant owners and stores that promote poor care on this forum, yet with so many bettas produced each year, many are either going to fall into one of these two categories, or if they are unlucky enough, both.
IMO quality, well-bred fish are usually going to find better homes because people don't usually buy expensive things just to treat them poorly. However, a $1-$2 fish is generally a lot less regarded and if it dies because of bad care, well then it's no big deal as it was only worth a couple of dollars.
This is why when breeding you have to actually have a customer base in mind. Questions I think all new breeders should ask include whether you are going to be selling your fish as pet, breeding or show stock? Whether you are going to only be selling to private customers or supplying local stores with your fish? Whether you are selecting for popular colours and tail types or just breeding the cheapest fish you can find?
Customer demand should be be a main driver in your breeding choices. It is no good successfully raising spawn after spawn if no one is buying them from you. Just because it's what you as a breeder like, doesn't mean that it's going to sell well.
Every store I go into has red and blue VTs that sit languishing in their cups for months and months. Therefore, it would not be a sound business plan for me to go out and breed red or blue VTs as this is an already oversaturated market and I would never be able to financially compete with overseas commercial breeders.
Therefore, it's not only the quality of your stock that dictates whether or not they should be bred, but also whether or not there is a market for the kind of fish you would be producing.