Uninstalled, did you even bother to read the rest of this thread? Or did you just jump right in with that mindless comment because you've read that firewalls are a good idea?

As several others said before, NAT provides adequate protection for most home users. Sure, we all know that defense in depth is a good idea when you're serious about security, but a large portion of the internet wouldn't have the slightest clue what to do with a firewall. For those people, basic NAT is usually enough to protect them from the big bad internet.