I wonder if a lot of the disagreement is just people talking past each other.
I used to think it was an oversimplification to divide the web into Documents and Applications. I thought it was more accurate to say it was a continuum, and using two different techniques was a sign that we still had not figured it out. After all, a blog post about programming might have an interactive example. An article about retirement might embed a calculator. If you try to categorize a site or even just a page as Document or Application, it gets fuzzy. But if you look at a page and just try to categorize it section by section, as Document or Application, it's easier. (Hence, Web Components make more sense to me.)
So anyway, most people spend some time surfing the web --- by that I mean visiting Documents. Clicking links from search results, to articles, to more articles. If you aren't using an adblocker, I can't imagine how you don't end up throwing your laptop against the wall. I ended up just turning off JavaScript for most sites, and the web looks more like how I think it should look. Every once in a while these people will post a rant, and it will resonate with most people.
But then an Application Developer will read it after a long day and say, hey, wait are you saying I should write my Application (like GMail) in jQuery? To be honest, Applications don't bother me the way overscripted Documents do. I almost expect them to be kind of slow. After all, even some Desktop Applications still have loading screens. So I don't mind so much if you're using React or whatever for your Application or even for that calculator embedded in the article about savings.
But for Documents --- like articles, blog posts, company home pages --- well, one thing I agree with SPA developers is that there could be less server-side rendering. These kinds of sites could often be compiled ahead of time into static HTML. Server-side rendering is better than SPA for these kinds of sites, but static sites are better than server side. I mean, who enjoys getting "Error connecting to MySQL database"? (Okay, that's rare.) I'm intrigued by the old-new JAM Stack :)