Umm, you mean lack of.. (intelligence, that is)
Smart man, that one. Obviously doesn't believe water in the air can skip condensation and turn to ice.
Whenever people ask me why the high flying jets make contrails, I just say it's like the exhaust of your car on a cold morning. Instead of that white vapour coming out of the tail pipe, it turns straight to ice because it's effin freezin' up there.
It's just easier that way.