The idea of a loyalty program is to reward individuals or groups of individuals for being loyal. Loyalty programs start becoming ineffective at the point in which an individual's loyalty begins to change. Delta Airlines, this is your current reality!
Contrary to popular Delta Airlines corporate belief, SkyMiles members actually want to redeem their miles for flights with both Delta Airlines and its affiliated SkyTeam partners (KLM, Air France, Korean Airlines, Kenya Airways, etc.). Claiming no blackout periods is only a facade if a SkyMiles member cannot gain access to flights when redeeming 3+ months in advance. The world is an increasingly global world and your arcane SkyMiles redemption policies need to reflect this. I am a Diamond member and I speak for the masses.