The ultimate equilibrium they will achieve if they do their job properly is that discs will not be rippable when they first come out, but after a couple months will get cracked. In that time period, the studio makes 90% of their lost revenue and you still have the ability to make backups after a delay. BD+ has had its ups and downs, but I think it has the potential to achieve this. It's more than you can say for most DRM systems.
Disclaimer: I am a co-designer of BD+.
If users knew that a key release is coming on a set date, it would remove a lot of the motivation for people to work on cracking BD+.
If there is enough demand for cracking a given disc, then users will pay higher prices for ripping software updates and crackers will put more effort into it. If no one cares about a given disc, then it may never get ripped (but no one cares so it doesn't matter).
Maybe publishers should release decryption keys for movies after a few months out using something akin to the street-performer protocol. :)
NB: Obviously I'm not advocating this, just trying out a thought experiment.
I don't even care, though. I'm just saying, you could do a lot worse as a hacker than to have the CS problems Macrovision gets to grapple with.