But that's probably it.
Most people have some time when they want to watch TV. While there's something on Netflix suitable they'll stay. But as soon as there isn't anything they'll look for alternatives and cancel their subscription.
It's that ages old beancounter issue. Making small "cost cutting" measures doesn't immediately lose you customers and increases your profits but it a) makes it harder to attract new customers, b) makes it more likely that regular customers will try alternatives and c) eventually triggers the regulars to be so dissatisfied that they leave and tell everyone "it used to be good but..."