1. Expressing interest in a girl at work without her express permission is "Sexual Harassment" and can get you fired and/or sued. Whether or not you're her boss. Whether or not you're actually being a dick about it. The girl who thinks "I wish he'd just leave me alone" is a constantly promoted image; whereas the frustrated girl thinking "I wish he'd just take a chance" never gets any airplay at all. "No Means No" has wound up becoming "No Means You Already Went Too Far, Because She Should Never Have Had To Say No To You In The First Place, You Horrible Male Aggressor."
2. Damn near every movie we grew up with that had a central love interest theme featured the shy, sensitive nerd who originally had trouble getting the girl to notice him, but in the end rescues her from the horrible, aggressive alpha-male type that was using her terribly, thus winning her love forever. Watch enough of this pablum in your formative boyhood years, and you're going to almost inescapably wind up with the mistaken idea that girls all want men who are too shy to actually hit on them. Whoops!
3. The loudest feminine voices in media are generally the brashest feminist voices. Any random sample of mainstream media is far more likely to contain a line like "all sex is violence" than a line like "Dammit, I wish he'd just pin me down and fuck me hard." The very few female mainstream media voices that do promote any kind of dominant male behavior tend to be conservative christian nutjobs, which only hammers the nail in the coffin as far as the image of men acting like men as rational and acceptable behavior.
The net result? Most of the men who are sensitive enough to pay attention to their surroundings turn into gender-apologetic wimps because they think women hate their gender. Meanwhile, lots of women - most of whom do want some aggressive behavior from their men - wind up turning to total assholes to get their fix, because the assholes are the only ones insensitive enough to the constant media sandblasting to still act like men. This gets them even more irritated with the assholes, which in turn feeds yet more negative stereotyping towards non-passive-aggressive male behavior, which even more strongly feeds the more sensitive males' perception that they need to act like wimps, which... it's a nasty, vicious cycle.