Does it always have to be goodbye?

Why do people think that at the end of relationship that you are required to lose that person. Why is it so hard for people to just realize that just cause they didn't work out in a relationship that they cant be friends anymore? Why cant people just say "Hey, you know what, we didn't make it in a relationship, we just weren't right for each other that way but, you are still a cool person and we should be friends."? I mean there have been some people who have been a big part of my life and then vanish with barley so mush as a good bye just cause we were right for a relationship like that.
I have always been one just to try and see it that way, that all breaking up means is that you just aren't right to be with each other that way. But I mean there was obviously something that made me like you and want to be your friend before and has that thing really changed? Why cant we just be friends after a relationship with out people thinking that it is weird. I don't know maybe I'm the weird one on this or maybe its because I just don't like losing people, maybe its because I try to see people as people, and try to treat them all the same whether we are dating, friends, co-works or even just strangers. Well at least I say I am this way and I do these things but who really knows.
I have had a few people who i have been able to keep as friends after a relationship and from what I can tell it has been great we have almost been closer then some of my other friends, because there are things that you tell people when you are in a relationship that maybe you wouldn't say to your normal friends, and so after you are almost better friends cause you know more about each other. But then maybe you are suppose to go your separate ways after a relationship. Maybe it is for the better of both people, maybe it is a way of taking what you have learned from this experience and move on and apply it to new places and people. But to do this do you really have to stop being friends with the person you once used to love? Well i don't know what the right way of doing it is but for me i wish to try and stay friends with some of the people I date. I mean maybe some of them show there true selves to you when you are in this relationship and that is why you break up cause your true selves don't mesh, and that is completely understandable and ok to go your separate ways afterwards, but not all relationships are like this. Sometimes it just doesn't feel right or the feelings fade. You cant control what your heart feels and what happens, so why punish a person for it. Why stop being there friend just cause they don't feel the same way as you?
Well now I think I am just rambling, but I think that is kind of the reason i started this whole blog thing so oh well :) I just wanted to get that off my chest. so for now, I bid you all a good night TTFN.