A word many forgot. Value. If there is value in buying a game or service then people will buy it. I didn't buy Batman A.C. until it was $10 bucks. Why? That's what it is worth to me. $60? No game is worth that to me. There isn't any value in it. It's that simple. I played Eve Online and paid $15 a month for it, it was worth it because the service they provided (uptime, patches, content, etc.) was worth it. It had value.
"Why pay for it when you can copy it?" Because it isn't worth my time. I go to Steam, see if there is a deal for something $10 and if there is I buy it. IT's not worth my time running around digging through spyware infested Torrent sites to sit around for 6 hours while I try to download it only to find the last 5% of it is only being seeded by 2 peers. I get patches, content, dlc, multiplayer, etc through steam and what is even better, I don't have to do a damn thing beyond click Install and maybe, maybe once in a while fill in some info.
Gates was right, the future is Software as a Service because people don't want to pay for software but they will pay for service. Much like people eating at a Denny's\Embers: you aren't there for the food. Everything there you could make yourself (copy). Rather, you are there for the service. You want someone else to cook it and hopefully someone competent and cute to bring you said food.