Comment by Klathmon

It's not "screwing" them, you said it yourself. They can't provide adequate support to all of their customers (in this situation, customer is defined as a content creator), so they are reducing the number of customers that they take on (by making it so you need a specific number of views-per-month or subscribers before you are eligible for monetization), and are reducing the number of current customers they have (by demonetizing the videos and categories that advertisers like the least)