A consumer coffee maker will not be designed for handling 50 people requiring a cup of coffee every two hours.
The other limitations, particularly regarding space heaters and fans, usually come from fire insurance. Your premiums will be substantially lower if you prove your business gets regularly inspected for compliance and that electrical appliances get regularly checked if they are properly installed (i.e. no stacks of extension cords, no damage on the cable from chairs rolling over it or from floor tank lids).
In contrast, home fire insurance will often have priced in damages from such unsafe practices, and a no-pay clause for gross negligence - particularly the latter is what any reasonable business will be keen to avoid given the disastrous impact a fire can have.
I don't disagree that a simple drop coffee maker is not designed for "commercial" use like that. But there's very little that can go wrong inside of one of them, with maybe the exception of the heating element. That failing wouldn't result in a safety issue.
The other limitations, particularly regarding space heaters and fans, usually come from fire insurance. Your premiums will be substantially lower if you prove your business gets regularly inspected for compliance and that electrical appliances get regularly checked if they are properly installed (i.e. no stacks of extension cords, no damage on the cable from chairs rolling over it or from floor tank lids).
In contrast, home fire insurance will often have priced in damages from such unsafe practices, and a no-pay clause for gross negligence - particularly the latter is what any reasonable business will be keen to avoid given the disastrous impact a fire can have.