Ah yes, just be independently wealthy.

Many working novelists have described being pressured by their publishers to write whatever the publisher believes will sell, and many have given in to the pressure because ultimately they need to eat. Arthur Conan Doyle famously kept writing Sherlock Holmes stories despite hating it, because the public and his publishers demanded it. The foreword to Ursula K. Le Guin's A Wizard Of Earthsea talks about how she was convinced to write a children's/YA book despite not really wanting to.

The post you're replying to maybe overstated things, but was much closer to reality than your post.

"Hating", no. He wanted to write books like The White Company. He could have done! But Holmes was more popular, so he asked a higher price, got paid, and continued with the Holmes. This is like a dialog with the public. It's not that he had instructions such as now make Holmes a vampire and was compelled to obey. The level of his obedience to the public was modulated by his level of liking money. Less money and more freedom was an option. I can't find the Le Guin foreword, but I wonder in what way she was convinced.

But anyway, no, you are not on rails in your creative "job", and it is self-directed, unless you think you're compelled to make X amount of money and thus have no choice but to write loathed vampire books, without even the option to go and work more happily in a factory.

Yes, doing bad things can have good secondary effects.