Wow, I think I need a shower to wash off the arrogance that came from just reading that page. I'd agree in premise, but officially, not even ICANN owns them; they only manage them. You shouldn't use them because of plenty of reasons. But you're totally allowed to, sysadmins everywhere will just hate you.
* http://jdebp.eu./FGA/dns-use-domain-names-that-you-own.html