Once in a while I need to take a break and I draw mostly personal work for myself and requests (since I chose who I want to do out of inspiration).

But, I let my commissioners know and it's usually just a few days, a week at the most, and two only if I don't have a lot on my plate and at least do a bit of work.

So I think in that case it can be ok to just do lots of personal stuff, but the artist in this case was way beyond that.