I wondered this too; I believe it's because we are discussing the quality of the food, which is masculine (maten), and not the hotel, which is neuter (hotellet). Were we asking if the hotel itself was good, then I suspect we would use godt.
Oh sorry!!! I meant to ask if 'er maten god på hotellet' would be okay also ?
I answered "Is the hotel food food?" and it was accepted. Would it be more accurate to ask "Is the food at the hotel good?"