I rely on WHOIS data to contact sysops of delinquent sites, it is completely reasonable that somebody be available to at least attempt to contact.

If you don't like the spam, use Google apps/Gmail for your technical/administrative contacts.

It is fair and reasonable, if you are operating a domain, to be available for legitimate contact. I accept the small amount of money and time I spend receiving spam phone calls roughly once or twice a month, in exchange for the important notices and communications I receive (and can make) every couple.