On site stuff likely paid minimal wage and not trusted change a freezer settings. Centralized management is cheaper (until it's not). But there are many ways to do it more secure than connecting the device to the internet and allowing incoming connections from any IP (how likely it was done).

Centralized monitoring, so you can check if the local staff are doing their job properly, and in an ideal world, detecting performance degradation so you can schedule maintenance before they break.

Defrosting.

That said, there is no reason for that to be remotely activated. You need to empty the freezer first anyway. I’ve had this same fight dozens of times, and with things that could directly kill people.”But we want to be able to update software remotely, and control (dangerous feature) via software.” The only reason iI’ve been able to push back on it is due to mandated hazard logs, which won’t pass with the above implemented.