How? Those people aren't paying them anyways. Removing people who aren't paying doesn't cost them anything.
In fact, those people are using bandwidth, which costs Netflix money. Removing them saves them money.
The way they are going they seem hell bent on removing those you are paying. In my case, I pay for 2 simultaneous streams. If I choose to share my password with 10 other people, there is a high chance I won't be able to use my own account at times, so, I should be careful who I share it with. Let them try enforce it, at which point they are welcome to close the whole account as they are not getting any more money out of me. I'm perfectly happy with the way Apple Music works and their latest price increase, so that service stays for the foreseeable future. But Netflix?.....It's barely worth it as it is....
Here's the thing. My wife and I used to live in her parents house, so we naturally all shared a Netflix account. We have since moved out, but I have not bothered to sign out of her parents TV. Also, we regularly holiday in Spain and have also signed in to the TV there. Sometimes, her father is there and we aren't, but he watches Netflix there. So, if my wife is somewhere else, I'm at home and her father is in Spain, what then? Only 2 at a time may watch, so what's the problem? No one is using any extra bandwidth, only that which is already being paid for.
I have Primevideo for €25/year, and to be honest, there is enough on it to keep me entertained in my spare time. The Peripheral is a good show. And, Amazon does not complain about password sharing; my wife, her father and I all stream separately at the same time. Even Disney doesn't seem to care about sharing. When we tried it, we also streamed 3 at a time, for just €10/month.
One last thing. With reference to my Apple Music thread. At least there you can listen to music and do many other things at the same time, such as drive and snowboard which is why I've clocked up 44 days of music listening in the last year. With movies and series you can't do anything else productive at the same time.
So come Netflix, try your luck. You seem to think you don't have any competition.