You can break this down as being upset about a pet friendly policy and being upset about the implementation. I agree more notice should have been given. As for the pet friendly policy as has been pointed out this not unusual at all in the hospitality business.
Go to bring fido website and you will see over 25K hotels that welcome dogs. From small boutiques to Sheraton, Hilton and Marriott up to Ritz and Four Seasons, hotels to motels to resorts. I know all of us on here like to think Disney is different (its the only way to justify paying for the same thing over and over again for average accommodations). Reality is that it is not different, it is still a hotel. All of these other resorts have examined the issue and have somehow survived biting dogs and allergy sufferers. People do not travel with their dogs that often so it is not as big a deal as everyone makes it out to be. These other hotels have probably seen the same thing. Has a dog had an accident in a lobby, probably, is it common - probably not. All I am saying is that this is not something new, pretty widespread policy and people are still able to vacation and have fun with and without dogs. Speculating about dogs relieving themselves everywhere is not really helpful and is not based on any real facts that have happened at other pet friendly places. Look outside the bubble and it really is not that bad.