Yep, some of his stuff is hyperbolic, etc. But will the right-er parts galvanize any learning (from better sources, later?)
It would be silly to argue with your points as, none is 'wrong'. But you are hardly an 'average photog', either; maybe you are not his audience.
My take is that the intended audience for his quick & dirty 'fix' for bad snapshots: is someone unwilling (yet) to invest the time and effort to Understand
(a great many) basics, starting with some physics and optics. Can no longer presume today, either: a random person can grok elementary algebra.
Ex: those awful presets? ... might could get a neophyte introduced to that and a range of increasingly powerful (and complex) alternative Apps.
Could.. or might stay in 1st gear indefinitely.
(Nor probably, could he (or you) tell a random person how to See.. a scene for its potential) nor how to decide which
--if any, of the possible manipulations is more apt to enhance/more apt to over-do or mangle the output image.
I guess that I expect little anyway--of such Intros; at best they can help a neophyte progress, but cannot make a Good photographer out of a person who cannot See a scene and its possibilities.. instinctively. For one who can See: there will be enough enthusiasm next, to bear the delving necessary to realizing what was seen--in the finished print. Including using some math and experimenting with what it tells you.
Maybe there are better Intros at this level; I haven't scanned enough stabs at it, recently. I think a tyro can grok DoF on the level of looking through the lens and Noticing the effect; stop-down and see: it's larger! (They were right.) But basic formulae follow, if one wants to grasp any Whys. The audience drops-off ~ there.
(Hell, as a tyke I learned the Need for [sq. root]; via Â-stops needing to be grokked! Ever thus?)
You could write a better one (even sans much math.) There seem to be lots of folks with Ferraris out there now, coming off a Morris Minor, all unaware of gears 4 through 7/8? Damn few shall become Tazio Nuvolari.