When the design crowd is lead to mediocrity, the results will always attract similarities.
Originality and uniqueness is hard to be observed among those.
Like you are looking in a candy store for the best chocolate...but how?....They are all sweet!
To a better understand:
http://99designs.com/logo-design/contests/logo-zeitgeist-electronic-music-art-project-22473/entries/94http://z8geist.com/It's hard to be original these days, but harder to identify something original.