This is a great question and I have no idea why. But if I liked the video, I'm afraid to click "not interested" because I don't want Youtube to not recommend similar content in the future.
They DGAF if you like what you see, only that they can hit you with more targeted ads from paying customers -- and boy howdy does the rile-em-up lobby pay big money.
As mentioned in a previous thread: you're the product, not the customer.