As an American, you're absolutely right. Both parties have dumb justifications for why they think the voting system should stay the way it is, but the reality

As an American, you're absolutely right. Both parties have dumb justifications for why they think the voting system should stay the way it is, but the reality is simply that the person/party in charge has no incentive to overhaul the system that go them there. They call foul and make a big fuss when the system doesn't work in their favor, but then they don't have the power to fix it. They've realized it's easier to just undermine the legitimacy of the winner and just patiently wait for the next opportunity. I wish I knew what it would take to get the support necessary to fix it without endorsement from a political party.