Then we're choosing the lesser of five evils, except now, none of the evil parties alone have a strong enough electorate to squash any sixth party that emerges from the disenfranchised of the other five. That's completely unlike the current two-party system, where no third party can gain any traction due to not having a sizable enough electorate to take on "the big kids".
> to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness