First and foremost, Sesame Street is entertainment, and now they want to make sure they are entertaining the PC minds of adult viewers more than the vibrant minds of the young. Do they really think there are kids out there eating cookies 24/7 because of Cookie Monster?
Perhaps the creators have been doing some pretty bad things in their own life, and this is their way of balancing karma. But, if this is making them feel guilty, they have a lot of serious issues unresolved.
PBS: Your tax dollars at work.