Designed to limit the level of intimacy of a relationship to be specifically platonic. The friend zone is probably the most duplicitous situations to be in, be it male or female because a person in this predicament is granted access to probably the most intimate and honest areas of a persons thoughts and feelings, but restricted from any and all romantic activities. This person is called upon for advice for relationships, called when there's a dilemma, and called for simple conversation and fun. This person understands, has compassion, and at times knows what is being thought before anything has been said.
The trust in this relationship far exceeds that of any romantic relationship that has been initiated, they are known and respected by friends and family, and from time to time they may be mistaken for your significant other only to be countered with "That's my best friend". This person possesses every moral standard and quality that is desirable however they must be placed in the "friend zone" to protect the integrity of the relationship.
In the most likely of realities and possibilities of alternate universes this person has a masters degree in all that is you! This person would love you like for god so loved the world but.... "friend zone"! This person helps pick up the pieces of pitiful broken hearts, listen to irrational reasonings, and never judges.
The friend zone creates monsters. The longer that person stays there, the longer they watch, the longer they see what is desired and eventually it's emulated. The friend zone is not safe.