Tyrion controls the White Walkers

Every time someone mentions White Walkers, Tyrion responds with ridicule. Why does an intelligent and well-read man not even consider the possibility? It’s obvious: He’s playing everyone. He controls the White Walkers and is lulling everyone into a false sense of security that they don’t exist. But why? Think about this. The Imp has had a bucketload of enemies all his life. What’s the best way to put one over those who’ve wronged him? Bringing a horde of ice demons to destroy them, of course.