Discounts are offered to fill empty rooms. Obviously they don't need to fill them because they are all booked that week (filling whatever quota they have). There may also be some sports event going on that week that are filling the resorts. I've always noticed that the blackout are the same each year. Holidays, pop warner, etc.
As mentioned, no need to reward anyone for booking early. Getting a discount often requires one to be flexible with dates and resorts.