Did you read the article? They specifically address this: This means it might well be faster from an end-to-end perspective to send JavaScript+HTML than JSON

Did you read the article? They specifically address this: This means it might well be faster from an end-to-end perspective to send JavaScript+HTML than JSON with client-side templates, depending on the complexity of those templates and the computational power of the client. This is double so because the server-generated templates can often be cached and shared amongst many users (see Russian Doll caching).