Air Conditioning is to make people feel comfortable. Idea temperature for human beings is between 26 to 28 degree celsius. Commuters complain of cold to IR because it is actually very cold at times (in many 2A and 1A coaches as well). Regarding your last point, if people want cold (and uncomfortable) temperature so badly, I think they may go by trailers which have freezers in it. Short point is, the temperaature should be comfortable.. no point of people covering themselves in blankets while awake. Thanks.