Who ever said media was supposed to be realistic?
It is because of the standard of looks used in media. Here is what they usually use.
http://tvtropes.org/pmwiki/pmwiki.php/Main/HotScientist
Just look at the, umm, dress code for more examples of unrealistic.
Your point is? The romance genre and individual romance plots are there for people who do care about them. Perhaps like a fantasy, people wish the stuff worked so well in real life. Or, maybe they just enjoy watching these plots unfold. If anything, the fact that relationships end badly so...
http://tvtropes.org/pmwiki/pmwiki.php/Main/DoubleStandard
^Read that for common ways each gender is portrayed in media.
Also, look through the rest of the website, it basically talks about all forms of media in portrayal.