I get the feeling it's the opposite. They didn't do any math and do it out of inertia or because "everyone does it", or because of the completely other and crooked reasons (like the article linked in the thread explains). DRM doesn't affect casual or non causal piracy - this was already discussed at length in the past here. Because once DRM is broken, piracy occurs using those DRM-stripped copies. I.e. it takes one pirate to break it in order for others to never deal with it. Therefore it doesn't lower piracy rate.

And I already explained how not using DRM can actually increase sales. And about DRM increasing piracy, there was an example from CD Projekt Red about their own game which they originally released with DRM (on disks) in parallel with DRM-free version (on GOG). And it was immediately pirated. But not the DRM-free version like you'd assume. It was the DRM-ed one! They said it was an interesting case study for them, which demonstrated that some pirates apparently break DRM for sport (i.e. who beats others to break DRM and pirate it). So it demonstrated for them that DRM boosted piracy. They never released games with DRM since, and advance the DRM-free distribution cause through their GOG service.

By the way, music is largely available DRM-free for quite a while already. You can buy DRM-free files on Cdbaby, Amazon or tons of other music sites. Which again demonstrates the point that DRM-free distribution works just fine.

> This is a huge industry with enormous power- why would they give that up over some upset rights activists?

That's exactly the point. DRM is all about certain control (over the market for example), but not about piracy. Surely those who have that control want to retain it. But they lie to the public claiming that DRM is used for preventing piracy, while really it's used for control. It just adds to the reasons to always oppose it.