If a pretty poster and a cute saying are all it takes to motivate you, you probably have a very easy job. The kind robots will be doing soon.
Sometimes the best solution to morale problems is just to fire all of the unhappy people.
Because nothing says "you're a loser" more than owning a motivational poster about being a winner.
Because you've given so much of yourself to the company that you don't have anything left we can use.