So no company can simply donate large sums of money, nor can any single person.
The goal is that individuals will be the largest donors, not companies, and that as everyone is capped in the same way, advertising will be a more level playing field. We don't want money in politics. At the same time, we want all parties to get their message out there, their message heard.
It's not perfect. There are issues. But this business of democracy should be taken seriously.