I'm totally guilty of this as well. Taken to its logical extreme, I find the same mindset also stops me from trying new things, as I'm generally terrified of screwing up.
Still, I find that perfectionism is actually a helpful trait for many of the things I enjoy. Programming without putting a lot of thought into your work beforehand tends to result in all sorts of pain down the road, for instance. And for me, my definition of "art" is something where you are in pursuit of perfection... for me, that goes for my drawings, my music, my Taekwondo, and my writing. In those things, perfection is precisely the point (or, at least, the eventual goal)!
However, I think your point still stands in that being frustrated at imperfection is a bad thing. I figure that you should be happy with simply being better than you were before... we'll never be perfect, but we can always get closer to that ideal.
Now, if you aren't getting better, THEN you're allowed to be frustrated. 