I somewhat agree, but many traditional publishers have an optional "pay for OA" model and more and more funding providers require OA. For journal publications,

I somewhat agree, but many traditional publishers have an optional "pay for OA" model and more and more funding providers require OA. For journal publications, we (in the EU) almost always have to pay. However, MDPI is particularly aggressive in its editorial practices and marketing tactics. In my community, we sometimes publish "smaller" works there: when early-career researchers get to guest edit a special issue in an MDPI journal and we want to support them; i.e., we sometimes fall for MDPI's marketing tactics ;-) It's best to have journals that are owned by the community, but these take time to grow into venues that administrators respect: we can publish some work there, but it's not enough for building a competitive academic CV. Considering this article: it's just a comment, and to me it looks like something an expert can easily tear apart. A well-established researcher wouldn't publish such a comment in an MDPI journal (as one of the other comments suggests).