Yea, I'm super confused on how this snippet of code is meant as evidence of un-separated concerns. He even says it contains styling, but it absolutely does not.

Yea, I'm super confused on how this snippet of code is meant as evidence of un-separated concerns. He even says it contains styling, but it absolutely does not. Sure, if someone does React incorrectly, they will inter-mingle code that could make working on it painful, but that's true of vanilla HTML/JS/CSS as well. Having developed using React for a bit now after years of using mostly vanilla JS/jQuery, I would never go back if I can help it. It's much nicer to write code that generates markup rather than code that manipulates markup.