It's understandable when you see that the ethos is to have software that represents the user in charge of the rendering, rather than centralizing it all on the server. There is a major difference between common "app store apps" or hostile javascript bundled with websites, versus software that's been written to work in the user's interest. However as they use similar delivery methods, it's understandable that it takes a minute to think through and revisit your assumptions that have lead to being default anti- javascript or app.

That makes sense until you remember what "rendering" is supposed to mean. Forming the HTML has no reason to be client side when you're using the site-provided experience. Yes provide a json version for other clients, but for direct viewing just send the paragraph of text in a usable form and let the javascript be an optional upgrade.