Here is what I understand. The computer does not have the ability to turn the AC on and off. So in order for the auto to work, it ALWAYS turns the AC on... because it can not, if you turn it off, turn it back on...
So lets say, it is 20 degrees outside, and you have the heat on, and has you are driving there is a nuke mushroom cloud coming up in the distance. When that heat wave hits you, the Alti can not turn on the air to offset the new 1200 degrees it is outside. So as a default it ALWAYS turns it on...
Also, the other reason for this is in the winter your windows may fog up more, and with the AC on, that is a lot less likely...
Anyway, your AUTO is not as smart as you think
