American Express Membership Rewards - Why is KLM not a part of the Plat 2-for-1 program?

Does anyone know why KLM is not part of the Platinum 2-for-1 International Airline Program given that Air France *is* a particpant? This seems odd to me since they're both effectively the same company, and especially since they've integrated their FF programs. I know that AF is generally considered to offer a better business class product, but KL offers some flights and destinations that would be more convenient and I'm willing to rough it in KL business class... :)