He responded to a statement in the article comparing solar thermal collection with solar + heat pump.
The article mostly talks about mechanical heat pumps, and you leapt to that, talking past him.
(I think both the article and him are not strictly correct: solar thermal heating has a place but is not typically a efficiency win).
That said, better house design gets you pretty much all the way there, and in places where you cannot design a house to get enough sun to heat it properly you also probably can't get enough for a solar collector to help much.
Can vouch for this. We've gone through three water heaters and a bunch of maintenance on those, and in the same time the solar collector has been replaced zero times and required no maintenance. It's honestly quite impressive.
I heavily vouch for them - the tech is so effective we cover them with a shadecloth in high Summer because the water gets too hot (Off-Grid property in Central West NSW, Australia).
Ours have lasted over 10 yrs without maintenance.
One downside is that they're not ubiquitous so some plumbers may not want to work with them.
They're so good I'm surprised I don't see them everywhere.