[i336_]

It would have been really awesome if USB was compatible with TTL-level (5v, maybe 3.3v) "serial". This nonstandard variant of definitely-not-RS232 is everywhere.

But...

> And the USB committee probably figured to be not fully compliant with RS232 would just confuse people, and damage hardware, so it was better to be not compliant at all.

...you are sadly right.

[throwawayish]

USB controllers have to support 3.3 V anyway (on the D+/D- pair, not on the SS pairs), for supporting USB 1.x modes.