> You've equated success with some kind of approval from others.

Yes, this approval is called "money to survive." If you don't self-promote, you are not going to get enough income to support your side hobby, which means it has to remain a side-hobby powered by whatever extra time you have left after your real job. That might not be much, if any.

Looking down on people for "shameless self promotion" means that you only want art from people privileged enough to have a job that can support it, or that are passionate enough to make significant sacrifices to their quality of life. We can deal with a little self-promotion so that they are compensated for their time and effort.