Controls have to be put somewhere, and networked interfaces mean fewer physical controls that may be difficult to access, tampered with or fail. Having a standard control protocol means interfaces can be changed and improved without modifying the hardware. They're not a bad thing.

However, having networked controls exposed on anything other than private, air-gapped, wired-only LANs seems rather foolish, to me.

Speculation to your question, for monitoring and control.

For monitoring, log temperatures and send error message if it gets too high. Data could be used if any legal question come up about food spoilage.

For control, I'm guessing there's times you want to shut it off or enable/disable defrost. Easier to do that at a computer than have controls that are either a pain inthe ass to get to, or too easy for some moron to mess with.

That being said, it should be on a local network and have no access to the internet. However a chain store would probably want the data sent to HQ, so the computer would need to be on the network.