Bullshit - you're talking out of your ass entirely.

This is a case of a dumbass enabling a protocol during dev/build, and forgetting it is in the GA build.

If I wanted super-secret way to get into boxes like this, it wouldn't be telnet. It would be a very specific port-knocking sequence (or single packet authorization).

Why would I want others to use my backdoor by leaving it advertised to anyone with nmap? That's stupid shit.