Oh, i don't knw there are several ways to do it just as they have cut out VPNs to a large extent. You're making the mistake that a lot of people do: that what is true today will always be a baseline of what is true tomorrow. If netflix is losing a great deal of money they will have no problems with the following: raising the fees significantly, lowering the rate but not providing additional logins or requiring a fee for providing access from remote locations. All of these things are feasible to do without much effort. And as my father would say when facing life and death, what's the loss of a limb?
I can see what you say happening after players start dropping out of the market. There won't be any upcharging simultaneous streams to multiple IPs for the forseeable future. The Great Stream War hasn't even started yet. Keeping things simple and flat priced are parts of having an appealing service in a competitive landscape.