I think it's a shame that more men don't take off time when their babies are born. For a first time mom, especially if you have a difficult baby or had a difficult labor, the extra help at home can be really valuable. And why shouldn't new dads have time to spend at home to bond with their babies?
But men almost never take more than a week or two off when their babies are born. So I tried to brainstorm why that is:
1) It's not "manly" to take off time for the birth of your child.
2) Since nobody else does it, bosses frown upon paternity leaves.
3) Loss of income since it's not supported by short-term disability.
4) If in training, that time will need to be made up.
5) Work is the only place for a new dad to escape his screaming newborn.
The main reason I think men should take paternity leave is because I think it might result in more understanding toward women taking maternity leave if both sexes are entitled to time off. Then we'll just all be hated by childless people.