> the rhythm of writing has to match the ideas in it

It's hard for me to tell what the point of the author was from just the part you quoted, but why does this have to be the case? I don't have trouble believing that many complex ideas require complex language to describe them, but the idea that it's literally a requirement in order for the writing to be "good" rather than just a usual circumstance isn't obvious to me. If anything, the complexity of this quote just seems to hide the dubious premise.