personally I can't get my head around an artist who isn't open to critique.
(As a frequent deviantART user...)
It depends on why you draw. Of course, people who frequent this site will find critique to be incredibly normal, and a very routine part of what we do.
For others, like casual "I just draw for fun" people more likely to frequent a site like deviantART rather than a forum like this, art is more of a personal thing. If you critique a personal thing, you're basically critiquing a person. For some people, critique is something you don't normally get, and something you never got adjusted to receiving on a regular basis.
The first critiques I got, I did not take well because I took it as a blow to my ego. It takes time to adjust to a lifestyle where critique is an typical part of the drawing process.