The author, by the way, has a separate explanation about why he promotes pseudoscience: https://supermemo.guru/wiki/SuperMemo_Guru_promotes_pseudosc...
From there:
> I am no guru, but when .guru domains became available, my colleagues suggested that only I could own that domain. We bought supermemo.guru in February 2014, and I accepted the position of the guru on the understanding that the world of SuperMemo is so specialist that it may indeed be hard to find a better SuperMemo Guru.