Like an earlier poster mentioned, should I start shooting at law enforcement officer type targets, because they could happen to be a crazed gunman like the one in California? I certainly understand your point, and don't disagree necessarily.
People of all sorts sling led at LEOs. I understand that. I'm sure that grandma is an active member in a very small number of those cases. I personally do not like the idea of our police officers shooting at targets of kids, women on playgrounds, and elderly in their homes. That clip of the old lady being taken down during Katrina comes to mind.
With that said, it doesn't mean that these targets are being used to desensitize LEOs. My guess is that they are being used for shoot/no-shoot scenarios. Scenarios that are confusing and tough to figure out. I don't mind that sort of training at all.