> It seems to me that in order to obtain the ability to build things that other people like, you need to go through the process of creating things they won't.

Okay, granted. What does that have to do with how the code is written? Do people generally care if a web app is running from nicely formatted JS or minified JS? Is a product manager not getting better at building things people like because they're not iterating on the code themselves?

Without agreeing or disagreeing with the premise, I think a relevant metaphor* here is that the painter can practice and iterate and go from creating crappy paintings to creating good paintings, without needing to make their own paint and canvas and brushes. If they're particular, they can have their assistant go to the supply shop and get just the right things they want, with increasing specificity as needed, but they don't need to manufacture them by hand.

* Like most metaphors, it's not perfect; please try to understand the intent.