That is because to be the most efficient they have to constantly adjust the deadzone temperature. Its not just monitoring but active control. This is based on local air temperature, humidity and stock levels. To be even more efficient they put a thousand fridges online so that a small team can do the work of a much larger local team.

So the real reason is that to increase profit margins, they consolidated lots of workers behind a few and did this via the internet. A common story the world over.