Well, I don't know why any business would block a country, that's nuts. The last two companies I've worked for did quite a bit of business with China (one had an office there). Sort of difficult if you block them.
I agree about businesses and AV - but you need multiple products to actually protect. I am building a new SSEP server at the moment, but we have two other AV packages as well in our infrastructure, along with our Sonicwall and our spam blockers of course. At home, one is fine.. if that. I haven't had an AV live protection product in probably 10 years on my home PC. Most live protection is of little use to be honest. Some is pathetic (Forefront, etc.) I do a ton of stuff on the Internet, I've never been hit or infected. Because it's other protection that's more important.
You do NOT "have" to limit IP ranges. That's ludicrous.