There's no techincal examination of Bel in that essay. It's a dismissive aside at the end, based on threads the author perceives in Graham's intellectual history.
There's a couple good comments in the discussion thread. In particular, there's a comment halfway down the page which points out that Bel's original introduction [0] has only a few specific characteristics (metacircularity, long contemplative period before implementation, formal methods) and that those have been core concepts in the Lisp community for decades.
If you mean https://lobste.rs/s/jec21l/thought_leaders_chicken_sexers#c_..., that's not serious criticism. (And like the other article, is obviously motivated by extrinsic animosity. Articles like that get reactions based on how people already feel. Those who share the animosity like the hit, those who don't don't.)
pg's idea for Bel was to express existing programming language constructs in the style of McCarthy's original Lisp, so to complain that it doesn't introduce new ones misses the point. You can't make serious criticism without knowing what the project was trying to achieve. (IIRC, Bel does actually contain a couple of unusual constructs for a Lisp, but not because pg was trying to invent any. They came up as side-effects of making the program clearer and smaller.)
Similarly, it makes no sense to complain that Bel isn't being used as a programming language. That's not its intent. Its intent is to be the minimal executable explanation of what a programming language is, in the way that McCarthy's Lisp explained what computation is. Obviously that would be unusably slow as a real-world platform. The important thing is that it runs at all.
