I've heard of a lot of guys having this problem, and I think I've figured it out.
The natural thing for most "nice" guys to do when they like a girl is bombard her with questions, compliments, date requests, etc. And we all know the result of that.
The natural thing for most "nice" guys to do when they meet a girl and do not like her (and the non HB's often fall into this) is to be friendly and polite, but distant. You avoid their advances, you tease them a little to get them off your back, you sound busy so they get the hint that you don't want to go out with them, etc.
Now look at those two examples, and apply The Game to it. Without realizing it, most "nice" guys are masters of the game with women they are not interested in. You are acting uninterested, preoccupied, you neg them, you appear to have other things going on in your life, etc. This is the foundation for why I hear so many nice guys say that they never get the girl they're attracted to and the girls they aren't attracted to are always attracted to them.
As you progress in the game, you'll probably find this happens a little more. You have a natural tendency to attract those types of women, and as your skills with women in general grow, those skills will grow too.
My advice is to get to know these women anyways. They'll be a good way for you to practice the game, and they will make you more comfortable around women in general. Test out new ideas and gauge their reactions. Let me know how it works out for you!