I haven't read the book, but I think your fears are somewhat unfounded. Skimming through it, chapter 8 discusses Supply and Demand (in fact, that's the title of the chapter). And it's certainly not devoid of math.
But much more concerning is "1.9 Capitalism, causation and history’s hockey stick".
It starts off questioning whether capitalism actually did cause the great hockey stick. It then presents the German case study pretty fairly but then ends: "We cannot conclude from the German natural experiment that capitalism always promotes rapid economic growth while central planning is a recipe for relative stagnation."
While it's true that one case study isn't conclusive (and the absolute term "always" was used to weaken the hypothesis), the closing paragraph leaves the reader with the impression that we only have one data point so we're not that sure which approach works better.
Edit: On the other hand, it is honest about price controls. And it does actually incorporate supply and demand curves in later sections where appropriate.
But it should raise some questions about who backs the school.
It's just that capitalism, sans monopolies, and markets are a natural fit for each other. Capitalism with monopolies is the late 1800s US, which was an economic disaster for many and why we saw a rise of unions and socialist groups at the time.