I fell these sort of opinions are at best disingenuous. There wouldn't be so many celebrations of subscriber milestones all around the creator's world if they didn't care about how many people are enjoying their work, yet they constantly are giving advices like "don't worry about your sub count".
You exist only till there are people who are aware of your existence, and same goes for your art. I have a couple of things that I really don't care how many people know about them, so I never even bothered to upload them online (and some - didn't even bother to create them in the first place... They're already as best as they can be inside of my head), but for things like my comics, yeah, I aren't creating for myself. That would be almost self-fellational, if you'll excuse my choice of words. I create them so that other people could interact with these pieces, and thru these pieces, with my imagination. If there's nobody to interact, there's a problem.
I sure there are people who are really write only for themselves without care about who might observe their art. But I also suspect that these people are also the ones who tend to just shelf their finished pieces, where they will sit until somebody decides to finally clear out this decades-old pile of paper left from the previous owner. Really the only moment these pieces of art have any hope on obtaining any audience.