I, too, have had them occasionally fail to leave a paper at my door - and as a Platinum, I should be getting a Wall Street Journal - which is even more hit or miss - along with the USA Today .
There could be many reasons the paper wasn't delivered - the employee that distributes the papers didn't show up, the hotel had more guests than papers or mabye another guest snatched yours. Who knows. You were correct to complain to the front desk.