Its not about the girls, its about the feelings of some guys~ If a men can't control his feelings he will turn mad, maybe evil and his mind won't be clear~ Its not the Girls fault, that some Guys are easy to crush mentally, thats why some pretty women can control us so easy, without us realising. Feelings are a complicated matter, but if you learn to be a dominant one, with a strong mind you will be able to control yourself, and even make most of the women, be hung up by u~ Im pretty sure, that Rin also liked Obito, maybe not as much as Kakashi, but at the end if things had not turned wrong, I think Obito could have get Rin, but well life is a misreable friend, who likes to play retarded jokes~
At the end, its Kishi showing us, how strong just some simple feelings of Human can change worlds. As Madara said, 'Hatred is born, from protecting love' or if u think more about it, it would be 'hatred is born from protecting your feelings'.
Naruto & Obito are doing this because of their emotional desires~
Its just stupid, if we say girls are the evil, no they are just more aware of their feelings, so at this part they are just stronger, but well men can overcome this = win~