Same reason website's are remote controllable. There's someone who's job it is, is to make sure the fridge is up and running, 24/7 and for the same reason that website operators/SREs don't live at each POP/DC, that fridge operator wants to remotely be able to flip some relays off and on to fix the problem without having to drive onsite, if possible. Additional, a single person/fewer people can then also be responsible for multiple/more sites.