Are Angry People Optimists?

Unfulfilled expectations are a frequent source of anger for me. I presume that people will do the job they were hired to do, companies will provide the services promised, products will work as designed. When these expectations are met with a disappointing reality an irrational rage bubbles over.  A video from The Book of Life, "How Not to Be Angry All the Time" does a good job of explaining how optimism is tied to anger and yet the solution that it proposes is one I am unwilling to accept.