score:4
At the end of the day it is your responsibility to make sure that you have the required Visas/etc for the country you are travelling to.
However it is the airlines responsibility to check that you at least appear to meet the required entry requirements, which would include having a visa for the country, or a passport from a country that does not require a visa. If the airline allows you to fly to a country without such documents, then in most cases the airline will be fined by the country you have arrived in.
Your comment that the airline staff refused to let you proceed because you didn't "slip him a $100 note" shows complete ignorance on your behalf, and is insulting to the airline staff involved. They were doing their job, as required by the country you were flying to. They DID have a valid reason to examine your passport, and they certainly DID care that it was valid.