... or studios have found a sweet spot they're happy with (or at least, not totally unhappy with) where spending more on DRM wouldn't be justified by the incrementally smaller increase in sales.
i.e. if you double your spending on your copy protection and it lasts an extra week before getting cracked, how much that extra weeks worth of sales is worth depends a lot on how many previous weeks there were before the crack. At some point the ROI curve stops making sense.
I suspect it's not pure business though - people in the media live off their creativity and seeing people pirate your stuff can be emotionally difficult. I would not be surprised if some places over-invest in DRM because they feel a moral and emotional imperative to defend their work from piracy as much as they can.
BluRay DRM is probably as good as you can technically get for movies distributed on discs. For movies distributed via the internet it's easier. But the economics of DRM are tricky - the key thing that hurt BluRay DRM (and the designers were fully aware of this problem) is that movie producers have a strong financial incentive to push player prices low, and player manufacturers have a strong financial incentive to push movie prices low. Movies and players are "compliments" of each other in the economics jargon. Not surprisingly, player makers make the absolute minimal effort when it comes to DRM and that's one reason why cracks keep happening.
One of the most obvious tension points here is PC software players. They're much harder to defend. But they increase the size of the player market (and therefore the movie market) a lot. So movie studios ended up deciding to allow them, despite knowing it'd weaken the DRM.
BD+ was designed to try and resolve this problem by allowing movie producers to spend the money on copy protection rather than player manufacturers, and it was remarkably effective for a long time. BD+ ended the era of open source players for good, only full time reversing teams that are willing to keep up continual effort on a disk-by-disk basis can break it. But in the end it wasn't enough for a fully convincing solution.
Impossible. I have no goals for DRM, except maybe to see it die. While I do not believe that DRM is currently related to piracy, it is hardly a bizarre idea that it is intended to restrict piracy... that is the stated goal.
DRM's stated goal was dealing with piracy, 20+ years ago. That does not mean that that is what it does now. Goals aren't results, to say nothing of the fact that goals 20 years ago aren't necessarily goals today. It is highly arguable that, given that it has failed to stop piracy comprehensively, that its primary utility to the people that use it is actually platform control. For instance, please see and think about the stuff discussed in http://www.antipope.org/charlie/blog-static/2012/04/understa...
One of the reasons I don't accept "DRM is about piracy and nothing else" is that it doesn't make sense of the observable facts. DRM costs money and basically doesn't work. If it were really about piracy, I think the "DRM is about piracy" theory would see one of two reactions to that fact: Either we'd see a great deal more investment into DRM than we do now to the point where it could actually be relied upon [1], or it would get dropped to save money. Neither is happening; DRM continues, its advancements are quite perfunctory overall, and breaks proliferate. On the other hand, "DRM as platform control" implies that the currently level of DRM tech and investment makes perfect sense, it's already the correct amount as investing a whole bunch more would not increase the already absolute control over platforms that it yields. So I am inclined towards the platform control theory, as it seems to match reality better.
As for the fact that the DRM users "say" it's about piracy... feh. Words. Words are meaningless nowadays. Look to the actions.
[1]: While "it can always be cracked" triumphalists haven't been looking, the previous gen consoles took an awful long time to be cracked. I'd say there's evidence that this could in practice be made to work for software, at least. The 3DS is still only pried open a bit, just shy of 4 years after its release, and that only recently! I wouldn't care to bet when the XBone or the PS4 get cracked; a straight interpolation of existing trends can easily suggest six or seven years. Music and movies are still going to be hard to fully protect due to the fact that what is output to the AV system is the content. Software allows for more opportunities for DRM.