Girl here.
We don't think shy guys are weirdos. Lots of people are shy. Being shy doesn't make someone weird or unatractive.
However, as 6 stated, we already have a pussy, we don't need two. If it's not just shyness, but total push-overness, noticable lack of self confidence, shadow-begging-not-to-be-noticed kinda thing, then that's different to just being shy, it's unnatractive, and girls will not like you.
It's not that we think men should be 'strong and forceful', it's just that we tend not to find total wimps attractive.