From my experience negative people = boring people, and boring people are the worst kind of people, because they can't bring anything to the table and they know it. So boring people can't rant or rave about great things, because they're too boring to get excited. They also have low self-esteem because they know they are boring. Because of these two features they criticize anything and everything. You have a great meal, and instead of complimenting the meal, the boring person compares it to a better meal they once had. I see it all the time. They don't want you to think they're suckers by praising something that isn't that great, so they don't praise much at all. Also by shooting down good ideas, they feel selective and they pretend they have high standards. To bad they're fuckin' lame.