Unfortuantely far too many people come from states where whois information freely avaialble on the net can cost them and their families their well being or their lives.
There are certainly countries with oppressive governments. But anyone who would ask a person in a situation like that to depend on some random registrar or registry's privacy policy to keep them from being disappeared would be an idiot.
This is not hypothetical. See http://www.informationweek.com/news/201802784
R's, John
Additionally, the argument that spammers will use other people identity to register domain is specious. You can ask Robert Soloway about this. I tracked one of the domains used by what appears to be his spam. It turned out that the person listed in the whois had no idea about the domain name, and it a credit card used without authorization. I put that person in touch with someone I knew at the FBI. A few months later, Soloway was arrested.