I think I understand what you're saying. It's a good analogy.

I think with art and creativity there is an element in which you're sort of presenting a piece of yourself to the world as well. In a way, a person is their art. It's a part of their identity, a part of who they are, so if the art isn't accepted maybe the person isn't being accepted. I think it can feel that way sometimes at least, in some circumstances and for some people. Wanting to be accepted and not wanting to be rejected is innate within us so I think it probably effects us on a conscious or subconscious level. I'm not saying that these things apply to you I'm just talking generally. The brain is powerful and mysterious in a way. We don't always know why we feel, think or behave in the ways that we do.

This...But how do you know that you don't suck?

It would seem that you dont suck.. lol 5000+ views seems pretty successful to me, but we all measure success differently as well so that is for you to decide.