If you update the firmware you're at a different level altogether (above it said 'device drivers', not 'firmware', they're definitely not the same), but still, the hardware hopefully has a failsafe that will shut down the motherboard as soon as you reach a critical temperature over the one where the fans would have normally come on, and past the highest setting for the automated shut-down in software in case of overheating (that's a 'nice' shutdown), presumably that one is one that you can still recover from without any damage.

Designing good hardware is hard, but it definitely can be done and a few ntcs and a crowbar are not going to break the bank.

You make a great point about why passively cooled systems are better though :)