No, there's not “a few exceptions”. It's really rather common for aites not to display in Reader Mode at all; far too common to be called “exceptions”, and nowhere near “a few”.
Not particlularly angry (at you, not at all; at web sites, a little), just a very different experience than yours: Many articles I come across refuse to display in reader view.
What's "forced reader view"? If I could force it (and get a readable result every time), there'd be no reason to be even a little angry.
Press CMD+Shit+R to force reader view, it usually works if it's an article. On iPhone I think you can force reader view by long pressing the reader button on the side of the URL bar.
But the linked article opens fine in reader view for me. You can also force reader view for any site in desktop Safari with CMD+Shift+R