I interpret this not as a pessimistic, “people suck.” But rather, a catalyst to, “simply start.”
Nobody cares in the same way one cares about one’s own projects and ideas. Obviously nobody cares like that! But why do we—ok fine yes I’m projecting my behavior onto you… Why do we look outward for the external validation? Certainly, the real world is the ultimate arbiter of truth. (As opposed to one’s thoughts.) But no amount of external data is going to create or destroy your true passion. If you have a project that you cannot put down because you’re passionate about it to the extent that it consumes your life, then whether or not you have external validation is irrelevant.
Do the thing. Make the art. It doesn’t matter that nobody cares. Do it yourself.