Amusingly, if you query GoDaddy for "godaddy-is-an-ongoing-criminal-enterprise.com", they claim it is "unavailable", although it's not in "whois" and other registrars say it is available. I was curious to see if GoDaddy would actually register that domain for themselves. Network Solutions used to do that, which was really annoying.
GoDaddy is likely blocking registration of any domain with the string "godaddy" in it, likely for entirely legitimate anti-phishing reasons. If someone got e.g. godaddyauth.com (or similar) and started phishing with it to try to get people's login details, and a WHOIS even revealed GoDaddy as the registrar, a lot of people might fall for it. Keep in mind that many people don't understand all the distinctions between registry, registrar, and registrant, and that WHOIS output often gives you details on all 3.