Yep. These methods were a result of needing to pay bills each month. The biggest point of pride was completing a novel, publishing it, and then doing it again.

The individualistic creative injections were still present, in the execution of the project. So, there's still room for your creativity and passion, but filtered through the pressure of productivity, and "mill" writing.

The advantage is to apply that industrious approach to your own work, and self-publish.

The advantage is considered an advantage in contrast to underpaid and overworked ghostwriting.

If you're not pressed to ghostwrite, then writing this way is not a priority.

I'm more interested in what art can I make that people will want to buy, these days, than art in and of itself.

Genre fiction is just writing for a pre-existing market.