tl;dr: governance is hard, there's no silver bullet, every system may be tricked. "good blockchain governance" would rely on gathering the result of multiple "coordination flags" like a user vote, a coin vote, core dev decisions, etc.

Very complete "here are the limitation, in the end, just don't be dumb" article.

About the bribing part: Could we get rid of it if voting is anonymous (I can't reward you with a bribe), and we give right to coins that haven't moved for a certain amount of time (I can't ask for your money and your account has to be "old enough") ?