It was fantastic, in the years Apple ][ was released. Far fewer children would have gotten into computers without it. Bad habits you learned were easily corrected in a CS program.
I wrote an almost-game once in basic that ran a pacman around the screen, but it was too slow, so I learned enough to rewrite the sprite animation in assembly. At first, it didn't work; while there were no errors, the animation never showed on the screen. It took me three days of debugging to figure out that it was working; it just animated so fast you couldn't see the sprite animate across the screen. I think it was the singlemost revealing aspect of computer programming that I have ever learned.