Commodore's BASIC 2.0 was already in ROM on every C64 motherboard. You can't just add Simons' BASIC to the ROM without a hardware revision, and doing a board revision costs money . The cartridge was the practical solution
That's a fantastic story. The "no experience necessary" ad is wild to think about now. It really shows how different the space industry was back then—and how a random moment can change everything. Sharman seems genuinely humble about it too. Thanks for sharing.