A lot of what's on that page is just nonsense. The page has a very clear bias toward one method and writes all sorts of unscientific drivel as a result.
I'm not in a position to judge this author's work as a whole, as this is not my area of expertise.
I know this person as an author of "super memo" algorithms for spaced repetition learning, so yes, he most likely have a bias, probably even financial stake to some degree, although not sure, I don't follow him in any way, so don't know if this ever was or still is the case.
In the past, I've used some of his algorithms in particular, with quite interesting results - subjectively speaking, not in any scientific regime, And, obviously, those are just one of many. I also remembered this was his area of interest in general, so assumed his wiki to be of some interest in the context of discussed article.
Thanks for your critical opinion, it will contribute to my priors about his writing.
I enjoy browsing r/Anki from time to time, and that site is frequently mentioned there. Spaced repetition is definitely a real thing, but the rest of the SuperMemo site is a bit “crazy”. The author does have a “20 rules” for good card writing which is pretty good advice though. http://super-memory.com/articles/20rules.htm
