It's not really a problem to lose money on some users if they are making money over all. And they are, because Youtube is very profitable and drives billions of dollars in ad revenue a year. They never really cared about every user being a profit generator for them. Except, last quarter, they missed their ad revenue growth expectations—as did much every big company around—and they are freaking out. That's what this is. It's not a question of whether Youtube can afford to keep the lights on, it's that Alphabet wants them to be continually _growing_, and this seems like a way to do that. I think Netflix empowered them to do this by cracking down on shared passwords, which was successful for them (at least in the short term).