So I am unsure of what you feel is wrong.
If you groom a successor, you have to think about your existing customers. If you simply quit and tell them to pay for the successor again, they are not going to be happy.And when you want to quit? Either:
a) groom your successor, or
b) freeze development and work under an alias for the rest of your career
I have no shortage of alternate names.
And if you disappear... well, that's just a big F*** YOU to your customers. Not very nice.