To "normalize" is to make something to become more typical or ordinary. I read the article but didn't find the word used there. I agree with Alfie Kohn about most things educational and back in the 90s sponsored him to deliver a televised speech. However, I believe homework can be meaningful and educative. I think the research he sites is about homework as generally assigned. Most of it is either just practice (math) or worthless (looking up vocabulary).