People took his code and re-distributed en-mass. BASIC paid the Microsoft bills for almost 4 years. Are you saying people stole and/or paid for unusable code?
Buggy, lame code still let you do something with your shiny new computing device. Early adopters will put up with anything. Which Gates understood very well. It was about timing, not quality.
Fortunately the quality of his software had nothing to do with his success. It was about marketing and business timing.