Author here, and yeah, I agree. I skipped writing a parser altogether and just split on whitespace and `|` so that I could get to the interesting bits.

For side-projects, I have to ask myself if I'm writing a parser, or if I'm building something else; e.g. for a toy programming language, it's way more fun to start with an AST and play around, and come back to the parser if you really fall in love with it.