It's kind of amazing how much certain data (in this case, a record in DNS) comes to mean to people. And how much we come to rely on that little bit of data. And really, how much we trust the DNS system and it's maintainers. "Ruling the world" might be difficult, but "ruling the internet" appears to be a matter of controlling DNS and then mimicking well-known sites well enough to install arbitrary software on every PC and device on the planet via a nefarious auto-update. It's the ultimate MITM attack. Even better if you can take over the DNS system for a short period, get a few million installs, then put the system back.

tl;dr: He who controls the DNS, controls the universe.