It bothers me a bit when people say they have no interest in politics. Almost everyone has some things that they are passionate about, and most of those things can be helped by the right government policies or hindered by the wrong ones. Everyone who has the right to vote should exercise it to help shape the world into the place they most want it to be.
But I don't think that everyone should just get out and vote for some random candidate, or vote based on (for example) which candidate you'd most like to have dinner with - that's as bad as (if not worse than) not voting at all. Ideally you should have an informed opinion on every issue. If there is an issue on your ballot that you don't know or genuinely don't care about, don't vote on that issue.
I am guilty of not following my own advice here by not maintaining my right to vote in UK elections (my excuse is that it's an annoying amount of paperwork which has to be done every year, and I'm ill-informed about UK politics these days anyway).