Are you sure about that? I do not almost nothing about those early years, but I get the impression that what made the Apple ][ a success is that it got accepted as a office machine. It got that status because it had a case and a keyboard.

VisiCalc played a role here, too, but I think it came to the Apple ][ because it was (relatively) popular in business, and then helped increase sales, rather then that it made the Apple ][ popular completely on its own.

Now, why did the Apple ][ get a case to start with? I think that was more Jobs' than Woz's work (<http://allaboutstevejobs.com/blog/tag/woz/>)