We're seeing some of the '80s in the tablet world, there's iPad, Android, Playboy, even MS Windows. Tablets run on a dozen different and often incompatible processors. Some have GPS or 3G. The number and nature of the off screen buttons vary.
But to answer your question, computers are no longer a hobby, everyone uses them, at least in the developed world. Back in the day, a manufacturer could design something from scratch, you can't do that today. It would be silly to think that a small company could possibly design a better graphics card than NVidia with it's teams of engineers. Today's graphics cards have more processing power and RAM than a mainframe did in the '80s. As some one said, it's like cars, or mobile phones or refrigerators. People buy computers to do stuff, like photos, video, surf the web, write books.
The computer has grown up, moved out of it's parent's garage, got a job, had a family and in general taken on responsibilities.
