I have to mention that... Pixel art requires no skills in building whatsoever. Everyone can do it without any trouble. Therefor, most pixel art is just pointless. Even when the creator is at least making something up, rather than copying a picture they have in MSPaint, it still will not impress me in any way.
We really don't need people encouraged to make pixel art in itself. What is the point? There is no need for it. You are not going to impress ANYONE by it when it's a build by itself. More than likely, it will just be seen as an annoyance.
I often see people who do pixel art in itself, as people who are resorting to it because they do not know how to make a good build. So, they are resorting to pixel art because they are desperate to try to impress somebody. Sadly, they fail to see that they are just wasting their time.
Like Trader said, it's only good when used properly (as part of a build in context). Sadly, noobs are unable to grasp this concept, and I am willing to bet I'm gonna get flamed for this post.