As far as men to women is concerned it is disparaging that so many males treat their female partners like total trash. The sad thing is that these women put up with it, usually because they either do not know better or they feel they have no choice.
However, I want to encourage some women by saying what some guys treat as trash another guy will treasure. I say this mainly because of all the times I have been unappreciated and dumped for someone else. (It was either that or I left the person because I always dreamed of having someone in my life who actually shows as much interest in me as in himself.)
All I can say about this for now is that women have to keep their heads up high. For every one guy that does not think you are worth much there will be 5 or 10 more who would value you. I at one time probably did not believe this, but now I do.
Of course the challenge is to learn to love a guy that actually does want you around. This can take time especially if you are naturally drawn to conceited jerks who are constantly looking for greener pasture. Still, the journey is worth it once you actually meet that person who really does care.