Not everything has to be so positive all of the time. There are so many people out there who believe that having a positive attitude will literally cure all that is wrong with them, which is patently untrue. In fact, I would argue that desperately trying to be positive even when you're not in a good place does more harm than good. If you can't sit with the things that make you unhappy, then you'll never be able to confront and change them.
On a less deep note, isn't it a little bit fun to be a hater? A buzzkill? A Negative NancyTM , if you will? Being the Squidward instead of the Spongebob has a certain appeal to it. Being negative for negativities sake doesn't mean you're a bad person. You've simply got a realistic concept of the world that the other sheeple could never possess, and you refuse to hide it. At least that's what we're telling ourselves.