I'm under the impression that massive investment in DRM is more of a way to satisfy tech and (pirate) culture-illiterate humans while making deals for content. Even Steam needed to nominally do something and Gaben's position on piracy/drm is very well-known.
Why should such humans be satisfied?
Because they pay the bills.
>Almost every program which is even slightly popular has a crack/keygen anyway.
It's not about making sure its never cracked, it's about delaying the crack long enough to make money. Most video games and home movies make the majority of their profits in the weeks to months of release.
There are plenty of people who aren't opposed to paying for software, but they don't have any issues with using a cracked copy either. They just want to play the latest game in their favorite series as quickly and easily as possible. If you can delay the release of pirated copies and make using them inconvenient to use these people are more likely to buy a legit copy.
As for efficiency (no overhead for distribution etc) I don't really understand why do companies waste resources on technical measures of copyright protection in the first place. Almost every program which is even slightly popular has a crack/keygen anyway, almost every movie is ripped anyway, business users (pirating is more dangerous for them + they often need support) pay anyway (even if the activation form would accept any random string for serial), most of the users who download pirate copies would not buy a legal one (usually because it's hard for them to afford it) anyway (and that's how software like MS Windows and Office monopolize markets in developing countries where everybody just uses a pirate copy). So why to invest so much resources in DRMs, activation, genuine disks etc?