I think hair preferences differ from guy to guy.
From my own experience all of the men in my life have always preferred my hair long. Currently my hair is to my hips.
To be honest, having long hair has always helped me get a lot of attention from men. Some use it as an ice breaker and will ask me how long I've been growing it or how long it takes me to wash it.
Ultimately you have to be happy with your hair the way you want to wear it.
Keep in mind if you attract a man who loves long hair and you get involved, they may not want you to cut it.
I think you should do with your hair whatever you really want to do and then you are not tied to a hair length or hair style based on any other person's opinion.
Just my personal opinion of course. Good luck to you.