Do you believe that the people worst off in a situation have a moral imperative to vote against their own interests? To a large extent even being able to worry about the best interests of the country implies a certain level of luxury - that you have few enough pressing needs around your own survival that you can take the time to expend energy thinking about the country.
No. Obviously my point is that a system where candidates running for office can openly BUY votes is problematic. The problem is not the voters, it's the candidates, and the system itself.
> being able to worry about the best interests of the country implies a certain level of luxury
In a situation like this, it's doubtful if parliamentary democracy makes sense at all.