The content rights-holders are the ones dependent on the licensing restrictions. They're the ones who get upset when users circumvent those restrictions, not Netflix.
Netflix faces two threats: 1) economic loss from foreign subscribers canceling their subscription because location spoofing no longer works, and 2) economic loss from rights-holders suing Netflix for a negligently insufficient blocking system.
It is in Netflix's best interest to only haphazardly block spoofing, i.e. implement a weak technical system, as long as they can legally prove they are making a "best effort" to detect and block location spoofing. Of course, any semi-technical person knows that even a best effort will fail, because any sort of blocking system is an endless game of cat-and-mouse that Netflix can never win.
Basically, yeah, they're "blocking" proxies, but ;-) ;-) ;-), they know you can still do it.