If you extrapolate your statement out to the extreme case where somehow it was literally impossible to pirate ANY game EVER, then what you are essentially saying is the vast majority of pirates would just stop playing games altogether, and I think that is an absurd conclusion.
If you extrapolate any statement to the extreme it becomes absurd. The question is not whether any one person that every pirated a game would have bought it, it is whether the claim that 1 download = 1 lost sale holds any merit. It is the claim the game producers are making with their calculations on lost sales, and it is clearly an absurd claim.
The much more likely case is that every person has the ability to pirate a game, and each person makes the decision to pirate or not pirate based on their morals, their financial situation, and the difficulty of obtaining a pirated copy of the game.
This first statement is clearly not true. My 65 year old dad does not have the ability to pirate peggle, but he has bought it.
So, we have one case. People that buy the game that can not pirate it. I think this group is bigger then you believe. I know lots of people that play games that can't install the game from DVD with out assistance if it does not autorun.
DRM does nothing but harm this group. They would have bought it anyway, now DRM can just get in their way.
People who refuse to pirate games on a moral basis can be discounted for this purpose, as they are paying customers.
It seems that you are in this category. I don't know how large it is, but based on the outcry on every forum I am a member of, it can't be too small.
As you point out, DRM does not profit the company with this group either.
Then theres the people who simply can't afford games (I pirated a few games back in my teen years simply because I had no income). If pirating became impossible, almost all of these people would not purchase the game legally.
A clear group that shows pirating does not equal lost sales. This group is much large then you suppose. This group basically consists of every PC game player between the age of 8 and 16. Check my math, but that is a large number, right?
I would guess these people don't make up a large percentage of piraters because most people who can afford computers can also afford the games.
This group does not afford computers, their parents do. And their parents don't give them $60 for games every other week. They are allowed to occasionally buy games, and get them as presents, so I would say maybe 1 in 20 pirated games from this group would have actually equaled a lost sale, maybe not even that many as those presents are still bought, as are the new games.
Then theres the people who are morally okay with pirating, and because of the ease of pirating games they choose to do that instead of pay for it. My guess is that these people make up the vast majority of piraters, and if pirating suddenly became completely impossible for some reason, many of these people would become paying customers.
I would guess these people make up a much smaller group then you think. To be good at pirating you have to be knowledgeable and spend a lot of time at it, otherwise you get crappy hacks that just install malware on your system. Much more time then people with the disposable income that allows them to buy 30+ games a year have. No, these are the bored geeks, the ideological, and the poor. Of those, the bored geeks are the only ones that would buy, and even they would only buy maybe half the games they pirate.
Hell, when I was a poor collage student I pirated games, and I don't think I even played half of them. Most games were collected so I had something to trade when a game I wanted came up. Today that would be the equivalent of building up ratio or cred on 0-day sites.
It will take time, but somebody is going to figure out the magic recipe that allows their loyal paying customers to enjoy the game hassle free, yet be enough of a deterrent to pirating that most of the people who would consider it just won't want to deal with the hassle. If they don't keep working at it though, then it will never happen.
No they won't. It is not even theoretically possible. Computers copy data. It is a core definition of what a computer is.
As my Comp-Sci professor used to say, 'if you want to keep them from your data, you have to unplug the computer and lock the door. But then it is not much use to you.'
DRM is a failed concept. Digital content providers better be working on a new business model, this one is doomed.