alphonso said:

It's an International Driving Permit, not licence. The licence to drive is the one you hold in your home country. The permit that this thread is about is just a translation document. It's not a licence at all.
And whether you have this translation document or not, just like we all know, if there's an incident it's gonna be the bule's fault anyway.
That's true. The "logic" is (or used to be), "if you weren't here in the first place, the 'accident' wouldn't have happened". Hard to argue with that.

As for:
In a nutshell, in a traffic incident here in Bali an International Driving Permit won't save you.
No - but if you survive being beaten to death by concerned locals, your insurance company will want it.

Driving cars or riding motorbikes around Bali without a "proper licence" or International Driving Permit, is plain stupid. What locals do has little to do with it. It gets really important if somebody gets seriously injured or killed, no matter where the "fault" lies.
The "fault" may be ambiguous, but telling the police you were unlicensed won't help matters.