Why don't men like to cuddle?
If we're talking about cuddling after sex, then the reason men don't like to cuddle is the same reason women are able to have multiple orgasms. After orgasm, men enter a "refractory period." Changes in blood distribution and hormones make it impossible for us to have another orgasm and we return to a pre-arousal state immediately. What's more, we couldn't even get aroused if we (you) wanted. We become totally uninterested in anything having to do with sex, desire, and courtship, which includes cuddling. We basically morph into your de facto gay companion. Without sex on our mind, we finally able to open up about ourselves and get to know you.
Us: "Oh, you're in graduate school? Since when?"
You: "Since April. Two years ago. When we met."
Us: "Really? Well that's just -- that's just great. Good for you. I mean it."
This phenomenon is so common that it's earned its own name: pillow talk. The whole process makes sense when you think about the big picture. By bonding with you we're encouraged to stay with you and invest in you and our budding offspring, giving little Edahn Jr. a better chance of survival. These behavioral patterns were coded in our ancestors' DNA which was passed onto us and now, onto into you. Since women don't enter a refractory period they're still aroused after sex and still interested in cuddling, kissing, etc. On the plus side, they're able to have multiple orgasms. Trade?
If we're talking about cuddling at other times, then the main reason is because we just want to get to the orgasm. Cuddling is like watching previews before the main attraction. FAST FWD PLS. THX. A secondary reason is that men don't like feeling vulnerable and dependent. It's not a position we're comfortable with. We prefer to be independent and self-sufficient. Cuddling usually involves some measure of mutual neediness, so we prefer to abstain.