The notion in its self was probably conceived by someone wallowing in self pity after being "nice" didn't get them sex (which undermines the point of been nice) they also see
people succesfull at getting relationships with women as "Jerks" etc... when in fact they are just jealous.
Being nice to a
girl doesn't mean they owe you sex, and if that's all you want from them then your not the "nice guy" your in fact a "Jerk"
The
girl/boy isn't "using you" when in the
friend zone. you are free to leave whenever you want but they probably do stuff for you to that you
don't notice seen as your so obsessed with having sex with them like help cheer you up when your down, they might do you a favor every now and then like any other
friend of the same sex.
If some other person gets the one you like don't think you are the only person that has true feelings for them. your feelings are no different than anyone elses
There is probably
people you have freind zoned so dont act so innocent either