personally i don't care of the age of the people i choose to be friends with. some are 15 years older some are even 20 years younger than me. you can get 50 years old and be a young at heart - and reading some the postings in other threads i doubt some have grown beyond their childhood years..
but i can understand young girls or women who don't want to be friends to older people namely guys. nowadays it's hard to distinguish a normal and sencere adult from a creep who's hitting on kids. if e.g. a guy my age is answering a request from a girl for help in a matter of homeworks in the language department it easliy could be a taken the wrong way. but if that happens, and it did happen to me, i'm not offended at all because it shows that the girls and young women are aware. i'm sad because i could'nt be of help. but on the other hand i'm glad that the young people here are confident enough to make clear they just want to have contact to people thier own age. and i respect that.
so what i'm trying to say is to some people age matters to some not. it's a thing of personal preference. as long as everyone is respecting that there should be no problem.