This is a fair criticism.

I think, if I had stopped at "hey look, Will Larson's model in this post wasn't realistic, this proves there's a bunch of people out there being mystical about system dynamics", this would certainly be a straw man -- but my argument went further. It's "hey look, Will Larson's model in this post wasn't realistic -- in fact, it's impossible to use stock and flow modeling to tell a realistic story about this subject matter, yet nevertheless here is system dynamics being peddled as useful in basically all contexts as a fundamental skill of leadership" which is not a straw man.