You seem to be assuming that since your neighbor's friend has been breeding since the '80s, but aren't making tons of money doing it, that there is something wrong with them.

Maybe they just aren't interested in making their living by breeding snakes? It is a big, hard job. It is full of risk... if your incubator has an issue, you could lose an entire year's income. Maybe they are just more interested in doing something else.

As far as what makes a good breeder, I agree with Ed (Freakie Frog) that customer service and quality animals (both in health and appearance) are extremely important.