I think it's inevitable in a large system with major democratic elements. Most voters won't do their research, since there is no consequence on an individual level for getting the wrong answer (one vote never decides an election of that scale). If you imagine a system in which all voters 1) voted only on policy 2) had well-defined policy preferences 3) had all the time and other resources necessary to research all candidates, then there would be no need for big campaign spending. Because voters are in fact very ignorant, don't have consistent preferences, don't only vote on policy, and think voting is a "duty" even if they haven't done their research, the whole project devolves into a PR battle, which is expensive.