The electrical system may be able to support a microwave, George Foreman, or crockpot, but there is no exhaust system in the rooms to handle fumes, and no garbage disposal to handle washing dishes. I for one would not be happy if I came to my room to relax and smelled sausage and onions, garlic toast, or burned popcorn wafting into my room. And I would have no problem complaining to the front desk about it, either. Also, just because they SAY you have to unplug it before you leave the room, doesn't mean that will happen. And if Mousekeeping doesn't unplug it in time, you could burn down the entire building, occupants and all.
(OP this wasn't directed at you, but at those who believe it's OK.) Welcome to the Dis!!