Because one person, one vote. I don't give two shits how many acres you own, you should get one vote (and that was the justification from the beginning -- a compromise so slaveholding scum would be overcounted). The country would have been so much better had Sherman executed the treasonous slavers, rather than burning the land. But alas, the story of the US is "well-meaning moderates" bending over themselves to placate backwater racist scum.