Because, often (though not always) you have to write in a different way to get them. It is hard to write well enough to make money purely for pleasure, as the e

Because, often (though not always) you have to write in a different way to get them. It is hard to write well enough to make money purely for pleasure, as the editing/etc process can be a grind trying to make everything smooth and pleasant to read. And with caveats the writers that are most famous tend to be ones who write big L Literature, which rarely makes significant money but is the stuff you hear about on TV in the news etc. There are exceptions but it tends to require more than a little bit of luck to hit the zeitgeist in a way to work out. Take for example Brandon Sanderson. Outside SFF I doubt almost anyone has heard of him but dude makes millions.