Get the HELL over it.
For real, I am so damn sick of seeing these "nice guys" whining about the goddamn "friend zone." Here's pro-tip number one: If you're in the "just friends" place, you put yourself there. Seriously. There are really only two ways for you to end up there (and I know, I've done both in the past).
Either: You made your feelings known to your lady friend (in a direct, actually-talking-about-it way, not some bullshit passive-aggressive hinting), and she made it clear that she was not interested in you romantically. If your romantic feelings for her are such that it's too painful for you to be just friends with her, then you need to back off from the friendship. If you all are that close friends, then she would probably hate to lose you. However, it's not her responsibility to date you to make sure you stay. If she just wants to be friends and you stay anyway, that's on you.**
Or: You have NOT made your feelings known to her. Regardless of the reason - you're too afraid to try, you already know the answer and don't want to make things weird, whatever - this is NOT HER FAULT. If you're just hoping that one day she'll magically "come around" and fall for you (and here we're probably back to that passive-aggressive hinting crap)... yeah, keep hoping. Not that it'll never happen, but you've got to accept the fact that it probably won't. You can't blame a woman for not making the first move on a guy she's not into. As far as she's concerned, you're a friend. Your lack of action, either towards or away, is what keeps you in the "friend zone."
|May not be the best model of a healthy relationship.|
Here's where we get truly problematic, though. This frustration can easily turn into bitterness and anger directed at the easiest target: the girls explicitly or implicitly rejecting you. This can turn into screeds railing against the shallowness of women who say they want nice guys but actually only care about looks and how stupid they are for going after assholes instead of recognizing that they should be with a nice guy like you, etc. Here's where we turn the corner from "oh, poor sad-sack nice guy" to "congratulations, now you're the asshole!" Because... well, let's unpack this a bit.
What exactly do you mean by "nice"? I mean, when we learned about adjectives in first grade, Mrs. Entwistle taught us to avoid saying things were "nice," because it's vague and boring. Those jerks your friends are dating? Maybe they are jerks, but they might also be funny, adventurous, smart, exciting, clever, fun, confident, or creative. Maybe not, but they're probably at least interesting. Would you want to be with someone who doesn't really show any personality beyond "I'll listen to your problems, and be safe and comforting?" You need to bring more to the table than just... "nice."
And are you really that nice, even? Do you get mad at these women because you feel like you're more deserving of their romantic or sexual attention than the guys they actually choose? I want you to think about that, I mean really think about it. You're basically saying that you're being nice and kind to these ladies not because they're your friends and that's what friends do, but because you expect their romantic or sexual attention in return. That's what we call being a bad friend. Nice people are nice because it's the right goddamn thing to do, not because they expect something in return and get pissy when they don't get it. They don't owe you a damn thing, beyond maybe being a good friend to you when you need it. Oh, and being a good friend to you does not involve them touching your penis.
|Let Morpheus break it down for you.|
Again, I feel your pain. As a teenager I did my share of grumbling about the girls who deemed me "the guy you wouldn't date in high school but that you'd want to marry" or "the guy every girl wants her best friend to go out with," and the ones who dated stoners who treated them like crap while I pined from the sidelines. But you know what? Even then I knew they didn't owe me their attention. And you can get away with a certain amount of grumbling, and maybe even bitterness and anger, at fifteen.
But if you're still doing it in your twenties or - Jesus Christ - in your thirties or later?
You need to get the hell over it.
*And I apologize for being all heteronormative in this piece, but it seems this is largely an issue with straight dudes.
**Oh, and if you use the not-being-friends-anymore as leverage to try and convince her to date you? You're not a nice guy. You're a douche.