Why?

Why are guys such weasles when it comes to cute girls?
I have tons of guys email me on facebook/myspace telling me i am absolutely beautiful but not one guy has the nerve to actually come up and talk to me. Am I that intimidating? I know I am a little just because I am really tall for a girl (just under 6ft). But seriously guys....grow a spine.
I am perfectly content with being single. That isn't the issue. I just wish guys would actually approach me instead of being little weasles and messaging me on myspace or whatever. This isn't high school.