Genetically speaking, you will get to a point where your projects no longer produce single-gene or less complex combos. But in most of our situations, this takes a long time. Sure, if you have “set out” to become a high-end boutique breeder and only own a handful of 5- or 6-gene animals, you might be in this boat already but for most of us that is not the reality.
Two things you have to keep in mind here:
One, don’t ever forget that there is a strong market for the less complex animals. There are plenty of people in this hobby that have a love for BPs and are willing to care for one as a beloved pet. But they don’t have $500 to spend on one. I don’t vend big reptile shows, only local ones, and I assure you, there is a market for the animals you are questioning.
Two, don’t forget about wholesale. Wholesale has been mentioned by other breeders here on other threads. Wholesale is not a “bad” word and it definitely has a place in the market. You don’t have to be a “big” breeder to wholesale your animals either - its mostly about making connections with the right people and ensuring that your animals are solid/reliable. The person who is buying wholesale to sell retail does not want customers coming back to them complaining that their pastel isn’t eating or whatever, so if you want to build a good relationship with someone who buys wholesale, make sure your animals are solid.
I don’t think everyone breeding ball pythons is just going to start culling on a mass scale because there are “too many” clowns on the market. For me, selling these animals both retail and wholesale are viable options that can be done successfully with just a little bit of effort.