it's all about the audit trail any more. It's damn hard if not impossible to track who logged in as root but if everyone has their own account and uses sudo for privileged access, you can log everything everyone does.
Yes, that's what my company (Motorola) did, on their network with 20,000 desktop systems and probably another 10,000 development/lab rackmounted systems. Actually, trying to set up sudo on such a disparate network would probably be a nightmare, so they gave each authorized root user a unique root username like "ray123_root".
Increasingly few Unix systems have active root accounts with passwords, they have a locked root account and instead use sudo — in part because of the benefits of the obscurity. I agree with the original poster, I would like to be able to change the root account name
Where is your Rescue Plan B, in case something goes wrong? On a "real" Linux system you can reset the root password and/or get a root login by sitting down at the console (or connecting a console TTY) and booting into single-user mode. Not possible on a router. The only thing you could do is fiddle with the buttons to force it to reset the NVRAM.
Removing the "root" username would cause no end of trouble. Heck, people are allatime getting stumped on simple things that can be found in the Tomato documentation (such as it is).
Still trying to figure out what a hacker is going to do once they get into your router. Reset the QOS configuration?