Too often, people want art–comics in particular–drawn for free. If not free, then for next-to-nothing, a slave wage. Sometimes with all IP rights transferred to them (hello, guru.com).
Then there’s the friends & family who don’t think art creation is a vocation. (Disclaimer: I’m not a good example to challenge this.)
Occasionally, a great thread will break out on LinkedIn. One was the inspiration for this strip, & I was given permission to quote two peers, one of whom asked not to be credited. That Rebecca O’Donnell was gracious enough (& believed in her opinion enough) to go on the record, I think, enhances the strip. [dead link]