I’ve been writing fanfic (among other things) for 15 years. I never found it particularly challenging to treat other cultures/demographics with respect. Learning about others’ experience is fun. I’ve made long-term friends that I never would have met otherwise. I’ve learned a lot about myself as well and it’s made life so much more interesting.
For profit-driven companies, the argument is always that they have to “cater to the masses” because that’s where the money is. If you’re writing for it’s own sake, the only limit is your imagination. The more you listen, the more you learn, and the more you learn, the better you become.
Seeing self-identified writers recoil in horror at the bare suggestion of considering a different point of view is a new and strange experience for me. Even if you only write smut, how many times can you write about fundamentally similar characters, doing more or less the same thing, with only minor variations in the theme before it gets boring?