I agree...
I view the hosts file as a thing, you use it to add/augment a service. For one thing it'll speed up finding a remote host, faster and less overhead than finding it over netBIOS.
Only on rare occasions, though, as folks have mentioned you'd do this when using the ISPs DNS, or a third party like OpenDNS that you haven't gotten around to configuring yet.
If there were some way to sync a current, fluid listing of the bad boys the last thing you'd want to do is have it writing to everyone's hosts file. That's a job for your AV or firewall.
So being an incomplete and ever changing target I'd save myself the labor and look elsewhere.
As Jack says this is a quick and dirty method and it does work, as well as you keep up with the listings anyway. I've seen a lot of home user-types do this. They stumble across the concept on the internet, or hear about it from their geek nephew or similar.
I just prefer to keep system files on client machines out of the mix, to the greatest degree possible.
