Why can't women just be HONEST with men?

I think women out there don't realize how difficult they make it when they are not honest with men when it comes to dating. They use lines such as "I don't want a relationship right now" or something that sounds nicer than "I am not attracted to you". Meanwhile, the guy starts getting a fool made out of him and waits, just because the woman cannot be upfront and HONEST. Most men can deal with a girl not being attracted to them, it's the mess and games that are created when the girl just can't be straightforward so the guy can go about his way. Why can't women just be honest and make everyone's lives easier?