That is what a UPS is for.
I agree with you. I highly recommend using a UPS all the time, and
especially when doing a BIOS update. However UPSs are not perfect;
they can substantially reduce the risk, but no such device can
eliminate it entirely.
Also, the actual update only took a few
seconds. It isn't like the old days where it could take over a minute.
The less time it takes, the lower the risk. But there is always risk.
A power failure is only one of the things that can happen. For
example, you could accidentally use the wrong update for your BIOS.
A BIOS update can be important if you are updating to Vista from XP.
Although I didn't need a BIOS update when I upgraded from XP to Vista,
I'll grant you the possibility that others may need one.
I am certainly not claiming that nobody should ever do a BIOS update.
I've done several of them myself.
My point is rather that you should do a BIOS update only when you need
to, not just because one is available. Unfortunately, there are a
certain number of people who think they should always be "up-to-date"
and will install every new BIOS update that comes out, without regard
for whether they need it or not. The result is that they occasionally
clobber their machines.
Again, updating the BIOS is inherently risky. I don't say to never
take the risk, but I do say to take it *only* if you need to.