I think they need to leave Cookie Monster alone. I still remember when they decided to have him "chill out" with the cookies and promote healthy eating as part of his schtick, which defeated the entire point of the character.
Turning Cookie Monster into a scientist is also a travesty, he's supposed to be a dumb-as-a-bag-of-hammers eating machine. It's his charm, and the entire point of the character.
I don't object to the lesson itself, or using Seseme Street to teach (it's always been the point) but they should do it with other characters, not with Cookie Monster.