If you don't like reddit's policy, it's pretty easy to take their open source code and set up your own clone. You'll likely run into the same issues at some point, though. There are always people out there that will want to do things that are incredibly detrimental to your business. Now that reddit is mainstream and one of the largest communities on the web, they're set up to be a huge target. You don't get popularity or legitimate money without policies regarding unsavory content.

In reddit's case, "think of the children" is a perfectly legitimate cry when the policy specifically is designed to stop exploitation of children.