Getting back to the original question, people get the "free" dining plan for several reasons. The way it worsks best for anyone is if you were already planning on staying at a deluxe resort, with the maximum number of people allowed in your room.
Lets say you're a family of four, two adults and two kids under 10, booked for a week at the end of August at the Polynesian.
The rack rate for a theme park view is $679.57/night. For a week, that would be $4756.99. With free dining, that would include the dining plan for everyone.
The discounted rate for the room is $577.64 per night, or $4043.48 for the week. Now add the dining plan at $67.33/night per adult and $24.22/night per child, and there's an additional $183.10 per day, or $1281.70 for the week.
So the total for the week WITH free dining is $4756.99, and the total WITHOUT free dining is $5325.18. You would save even more with free dining if your children were over the age of 9. With that scenario, your dining plan cost would be $269.32 per day, or $1885 in total. Your total package would cost $5928.72. In this scenario free dining saves you over $2100.
The THIRD option is to pay the $4043.48 for the room and pay cash for your food. As annual pass owners, we get 10% to 20% off some restaurants, and as DVC owners, we have the option of purchasing Tables in Wonderland. On our last few trips my three teenagers and I have spent an average of $175/day on food. If you were to do that with your room discount, you would pay a total of $5268.48, but your food choices would be different.
The savings go down the less people you have in the room, since the room is a fixed price regardless of occupancy.