I'm not, and my kids are grown so I can share all kinds with them. Also I'm not likely to miss any NSFK double entendres. But I think some people like a few places on the Internet that are adult-clever but safe to look at with their kids. And some might be less likely to realize the implications of a joke that might make it NSFW, either through language issues or their own innocence. Just as most English-first people today don't realize "hoist on his own petard" was another of Shakespeare's many fart jokes. So few in fact that it's now completely appropriate anywhere.