People leaving Aircon on even when not at home (Score 2, Insightful)

Jesus I cant believe how many people seem to leave aircon on during the day while at work etc, what exactly is the reason for this?? I am a UK expat living in Thailand...Thailand gets extremely hot and pushes 100% humidity regularly so aircon is wonderful however I only ever cool rooms im actually using and only when people are in the house, as does everyone else I know... If you cant stand being hot for even 30 mins while the rooms cool down can you not at least put things on timers to cool it before you get home from work??