That's very misleading. You don't need to purchase from WDTC, you can use any agent who then purchases the MYW package on your behalf. You are indirectly purchasing from them in this case, but really you're indirectly purchasing from Disney everytime you go no matter who you are dealing with up front.
As I said, I booked directly with Disney with corporate rates. It has nothing to do with who you book with, the sole requirement is that you purchase a MYW package.
A pp said it is unfortunate as it seems a good marketing tool, I sent them an extremely long winded and detailed account of how I felt it could still make them money and keep me on site even if I did not buy the MYW package, someone actually phoned me to say thank you and they'll forward to marketing, just because. On arrival in WDW 8 months later there was a beach bag jammed with cookies, candies, and some other things along those lines and a note saying thank you for the feedback.
It was nice of them, I made it clear in the email it was not so much a complaint as an I don't understand why and I think your company may not either (policy for policies sake is rampant in corporations today), and I didn't ask for an exception to the rules. The bag was handy for our two day trip to the east coast and beach, which probably wouldn't have been taken if we had the ddp, hahaha.