I agree with most of what they say, and I think the point is that we're uniquely bad at addressing these issues in the open-source world.
We accept a degraded UX experience (which I think this unarguably is from a normal user's point of view) because at least it's not proprietary lock-in. But it's a big reason why desktop GNU/Linux doesn't crack 2% usage. Inversely, I think this is _the_ core value proposition of Apple's ecosystem. They pay particular attention to consistent, unsurprising integration, and the Apple experience offsets their iron-grip over your device for most users. It's easier to convince someone to change how they do a task if you consistently deliver pleasant UX.
I recently had the opportunity to help a _very_ 'normal' user with their computing, and it was remarkably eye-opening watching them interact with their machine (Windows at the time, but they also use a Mac). Indeed, they hated Windows because it wasn't as consistent as a Mac, but Windows was dealing with their ambiguous interaction remarkably well I thought. Much better than a GNU/Linux DE would have.
If we want a world where normal people can use free software for their everyday computing needs this is something we need to get much better at. Forget 'normal' users even, these projects (and threads on HN) are full of _developers_ arguing back and forth that they find it infuriating/unusable. And unfortunately not many of us have the time and money to contribute code or fork projects to increase competition and spur improvements.
(also, hi again Jedd :) )