Block double logins. If another machine on a different IP tries to login the account could be blocked. The block could mean the account holder has to verify its them through email or phone. If this kept happening all the time then it would dissuade the account holder to be loaning out their password.
I agree it would make the experience worse for people. It would also negatively effect Netflix's stats.
Netflix and others need to make more discounted price offers and reduce the amount of geo-locked content.
Exactly - so they'd significantly detriment user experience.
The arguments above are that they could stop it if they wanted. Well, they could, but only through causing paying users problems. In circumstances where the law is being broken to their detriment, I don't have any issues with them lobbying for that law to be enforced, rather than causing their paying users problems.
People also raise arguments around business models, and geo-locked content.
Firstly, they are a hugely successful company which to some extent single handedly revolutionised online distribution. They are intelligent people, who will have thought about all the proposals people make. They have decided that their way is the best way for their business, and are within their rights to do so. If people don't like it, the answer is not to use the service. It's not to steal content.
Secondly, as to geo blocking, I largely agree that content should be released everywhere at the same time. But I've seen numerous examples - far more than you'd think - of this not being in the hands of the streaming platform, usually because a particular show has rights issues in a certain jurisdiction.