The odd thing is that form-based web applications must surely have right away seemed fairly obvious and familiar to people at IBM mainframe shops who were used

The odd thing is that form-based web applications must surely have right away seemed fairly obvious and familiar to people at IBM mainframe shops who were used to block-oriented terminals https://en.wikipedia.org/wiki/Block-oriented_terminal https://en.wikipedia.org/wiki/Block-oriented_terminal . The continuations-based design that Viaweb ended up using would be another story though.