Sadder still is when you know how you'd like your relationship/marriage to look and work and can express it only to have that view/ideal stood on it's head. Settling for some level of friendship, in the absence of a degree of certainty about a deeply intimate relationship, can often be tolerable in a no-win scenario.
The Captain
Friendship!!?!
None of my friends ever threatened to call the cops on me for wanting a healthy sexual relationship with my wife.
That woman is NO friend of yours.
SpinFree
And sometimes its as simple as this, through the betrayal and de-prioritazion of you and the mariage - they become no friend of you. Some of them make themself into your nemisis.
Actual friendship would allow for recovery of these bad situations, and I don't think many of us would be forced to be stuck in the "no-win" position of a forced sexless marriage. A good friend will accomidate to a limit, because they know you would do the same for them.