In Hamilton: an American musical, Why is Alexander Hamilton portrayed as the bad guy instead of Aaron Burr?

In Act 1, during the song " Wait for it " Burr says " Hamilton doesn't hesitate, he exibits no restraints, he takes and he takes and he takes, and he keeps winning anyway, he changes the game, he plays and he raises the stakes, and if theres a reason he seems to thrive when so few survive, then goddamn it I'm willing to wait for it". But why does he try to portray Hamilton as the bad guy?