system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can metal go into commercial microwaves in restaurants but not my microwave at home?
gpt
SOME metal is microwave safe - Most is not.  Rather than try to have home microwave users differentiate between good metal and bad metal, they just say don't use any metal, because the potential risk far outweighs the potential benefits of using metal in the microwave.  

In professional kitchens, there are some metal tools that they know to be microwave safe, and they use that specific tool in the microwave - but that doesn't make all metal safe in commercial microwaves.  They just know the difference.