I'm trying to figure out the logic that makes "free for commercial use with less than 700 million monthly active users" less open than "free for non-commercial

I'm trying to figure out the logic that makes "free for commercial use with less than 700 million monthly active users" less open than "free for non-commercial use", which is the traditional norm for non-copyleft open source machine learning products. But I just can't get there. Could somebody spell it out for me?