It's not that easy. From papers cited it may be easy to deduce who is the author. Typically, there are projects resulting in many papers, not single ones - so it is natural, and desired, to refer to previous works.
Additionally, it may be easier to find if an author is not committing self-plagiarism (sending the almost the same thing to a few different places).
That is also a problem with double-blind reviews, and I'm quite familiar with the problems (and annoyances) of anonymizing a paper. However, my main point was about making the reviewers sign their name. I am unaware of a CS community that does so.
Additionally, it may be easier to find if an author is not committing self-plagiarism (sending the almost the same thing to a few different places).
More on that topic: http://academia.stackexchange.com/questions/625/open-versus-...