We live in a Representative Republic. The citizens don't make, and rarely get a vote on, the laws created in Washington. We elect people who we believe most nearly represent our views to make laws on our behalf. The Second Amendment was written at a time when there was a great distrust of standing armies in peacetime and the framers felt it important to give the citizens a means to defend themselves against tyranny.
Example: Waco. Regardless of who's side of the story you believe the people on the inside of the compound believed they were defending themselves against tyranny and oppression. Were they wrong? Not my place to say, but I can say that the government has made some major changes in how it handles situations such as this.