A breakup is already hard. Take it from someone who had to break it off with a girl. Sometimes you dont know the reasons or simply dont want to spend ages explaining why the relationship isnt going to work. You're hurting already from the breakup itself. You just don't want to think about it. At least not for a while.
If you keep on asking why all the time girls especially might just get angry and say something they really dont mean simply because they're hurting so much, which could end up hurting you both even more. I think guys should try to understand the pain their ex is going through.
Guys, would you like a girl to go on and on and on at you asking you why you broke up with her, her aim always being to get back with you immediately after the breakup? I, for one would hate that, so give the women a little space when you've been through a breakup. They'll probably tell you why later when you're not so desperate to go back out with her again. You might not be desperate to go back out with her again, but that is how it will likely be percieved. And that's what i have learned from observation too.
Guys, are you really too stupid to work through what happened in the relationship yourselves to find the answers to the whys? Ask your friends why they think the relationship didn't work. They'll probably be able to give you some answers and they'll be able to be alot more supportive to you in your grief. You probably want support because you're hurting more than answers to the questions you're asking the answers to which can do nothing but hurt you more. A person whos hurting isnt ready to be hurt even more. There's a better time to ask the whys and such when you've both recovered from the breakup itself then you'll both be able to think more clearly.
"Why are guys so stupid?" Maybe that should be the sequel thread to this one?