Your counterargument is flawed - nobody banned anything. These were the choices made by a private company to its own product line in order to better serve its customers and boost sales. Apple wasn't even the first company to choose this route. In 1984 when the Mac was released the most successful personal computer of the time was the Commodore 64 - which had no expansion slots, relying instead on a daisy-chained external serial bus for expansion. The computer makers of the time realized simplicity was the key to mass consumer adoption and thus increased sales. I wouldn't be surprised if Jobs pointed to the Commodore 64 when insisting expansion slots not be present in the Mac.
That was dealer price, not retail price. A C64 system having the monitor and floppy drive retailed for $1,000. It was the highest-selling computer at the time (technically of all time) and yes, Jobs was obsessed with it. Jobs believed taking the C64 with its serial expansion bus, and adding in a mouse and a GUI would make a computer "for the rest of us." Also, that price you quoted is after the release of the Mac, which subdued C64 sales.
The Mac was released in January of 1984. These are prices from Christmas of 1984 - several months after the Mac was released. The design of the Mac began in 1982, when the C64 was retailing for $595 and was seriously affecting Apple II sales. What these catalog prices reveal is the impact the Mac had on C64 sales in a very short period of time, which forced Commodore to respond with the Amiga. But that's a story for another day.
