@xacrox, I’m aware that you feel that way, and I don’t know your friend, but I can tell you that it may seem like she’s okay with knowing you’re attracted to her, and says she’s not interested and wants to just be friends, but there’s a good chance (from my experience), that for her, she’ll never be able to act or feel the same way around you again, and she may feel like you don’t respect her self-identification as a lesbian, because you would entertain the thought that you had a chance with her.
Like I say, it’s only something to think about, because this is how I have felt in the past. A guy friend may mean so well (“I just wish I could be a lesbian,” was the nicest), but the fact is that they some how don’t appreciate that my sexuality is as concrete to me as theirs is to them (like @mangus said—not that you would necessarily be disgusted by a man being attracted to you, but there’s not a good chance that you would date him just because he’s such a good friend, if I’m not incorrect).
Ultimately, you have to know you’re friend, and just keep these things in mind.
Oh, and by “plow forward,” i didnt mean, like, physically :), i meant that they somehow think that knowing that a good male friend is attracted to me is some how anough to make me date a guy.