Magecrafter
Emptions, or rather desire; is the driving force behind social and civil advancement. A society can not experience growth without a desire for change. If man never sought to revolutionize travel, we could still walk everywhere. We could have retained the DNA that allowed us our natural adaptability to the natural environment. Instead, man sought a change. If you become emotionless, you lose the desire to seek a change. You become content, which is a path to regression. This is not regression in the sense of 'time', but regression of progress. If there is no growth, there must be regression/reduction/withering/decay. All life and matter decays if it is not maintained or pushed forward. Emotion is the driving factor for this.