The issue is a cultural one, where people are looking out for themselves over their country. Where politicians seek to enrich themselves, people just want to get a hand out, and lobbyists write sections of laws.
Where democracy shines is that we can leverage democracy to amend the constitution. If they think that moving to a pure popular vote or something would be better, then get that amended into the constitution, we have a process for this, just get 2/3s of states to vote for it.