If anything, this should've been a read-only, monitoring/alerting system.

I have something similar for my freezer because sometimes the door doesn't close properly and, well... I too dislike tossing out a lot of food because it spoiled. A simple £10 sensor and a crafty little rule in my home automation system (sliding window averages, stored as historical data points, live comparison + alert if value is higher than usual for longer than 5 minutes), and I know if shit is going wrong.

No supermarket needs remote controllable systems for a fucking fridge. Period. Set up monitoring, alerting, and some minimal local presence. Bam, you're done, if shit goes south, you can have a person there to fix it manually within 30-45 minutes. And hackers can't fuck up your food.