How did this property of MAOIs being the addictive component of cigarette smoking become known?

(probably government-funded research)

I see your point about bias being present in grants distribution, but there is no better way that is apparent. Too liberal, and you waste money on useless research. Too conservative, and you stifle important research that has no immediately marketable use. Scientific grant administration is difficult. As to government employees being in charge of grant distribution, who else should perform this function? Where else would the funding come from? The U.S. is a world leader in scientific research due to its generous (in comparison) funding.