I tend to be cynical, only because "cynical"is relative to peoples' subjective views on what "optimistic" is. People always want to believe the best in a situation because it's a natural coping mechanism. If I tend to be cynical, it's not because I like to be doom and gloom, it's because I prefer to take an objective view of the situation. I'd rather be a cynical and pessimistic realist than one of a multitude of blind optimists. But for most people, I think I'm speaking a foreign language.
One doesn't have to be optimistic, one need only take action in the direction they believe is correct. Then you can be optimistic in knowing your efforts will yield results in whatever path you choose (and have the power to effect).