Because men are people. Men, just like women, are afraid of rejection.
If a woman is giving “hints,” it means she’s too scared to be direct. Well, guess what? Hints are ambiguous. That means it is possible to misinterpret a hint. Men, like women, are also scared of rejection; men, like women, may not want to follow up on a hint because what if they interpreted it wrong and they get rejected?
Giving hints is a cowardly action. It’s a way of saying “I am too scared to be direct, so I want you to take a risk I am afraid to take myself.”