It has always been my understanding that Chris Walshaw invented abc about 20 years ago in order to take down tunes before he'd learned to read notation, then afterwards contrived a program/conjuring trick to enable abc conversion to standard notation and MIDIs via that nifty little onverter on cencertinanet. Don't think he ever intended it as a substitute for those who can't be arsed to learn notation, just as a temporary aide memoire that escalated into far-reaching digital implications.