Wow, I'm amazed at what an active thread this is--I can't resist putting in my two cents!
I don't care much about how many children anyone has, etc., but two comments from the original poster:
1--"How unfair is this?"
I don't really see this as a fairness issue. Disney sets its policies, and you can choose to vacation there or not. Whether it's about trying to get you to move up to a moderate or deluxe, or to get two rooms, or about planning for the use of amenities like the pool and food court and transportation, etc., or whatever, it's just a business decision, not a value judgment.
Nothing wrong with letting Disney know that they are missing out on your business because they don't offer enough alternatives for you---they can plug that in to their business decision-making process.
I see plenty of these things when I make reservations for travelling. I was just pricing out an en route hotel for our December WDW trip, and the special Expedia rate I was looking at said the room was only for two, contact the hotel, etc.
2--"how do families continue to go on vacation having to pay outrageous rates like the Poly, Wilderness, etc?"
A lot of discounts have been offered on these resorts in the offseason periods. As someone posted above, while it is true that these hotels aren't cheap, they aren't really much different from other luxury hotels in resort destinations (during whatever high season is a those locations). Again, I don't think they're outrageous--just priced according to the supply and demand.