You hold a very fundamental understanding of what "emotion" is. At the heart of it, beyond happy and sad, emotion is a driving force behind discovery - the curiosity that leads people to question the nature of the heavens and the earth around us. Abolishing emotion is the abolishment of intuition, and without intuition, progress cannot be made, as astute observation cannot be made.
War is made by the foolish, and suicide is performed by the depressed (or the desperately ill). These are not necessarily emotions, but handicaps in the minds of the individuals involves - one requires an education, and the second requires medication.
Emotions, when combined with a great intellect, do not cause conflict, but an expansion of horizons. Emotions, particularly helplessness, when combined with supreme idiocy or apathy invite acceptances of "things are just because they are" much like you have made today.
Sadness is a fundamental need of human beings, for without the bad times, there are no good.