Because not-laypoeople ale precisely the kind of people who would nitpick the technically incorrect title.

I'm a lay person w.r.t. this topic, and I assumed the great exposition was meant exactly for persons like me.

This is quanta magazine. It is for lay people. The reason people are "nitpicking" the title is that "shape" is not a technical term. The technical term for what was found is "convex polyhedron". I read so much of the article before I was sure that it was talking about convex polyhedra specifically because the title is so ambiguous.

Quanta Magazine is very much designed for non-technical lay people.

From their About page: Quanta Magazine is an editorially independent online publication launched by the Simons Foundation in 2012 to enhance public understanding of science.

Oh come on. Quanta Magazine basically writes for HN. They have very little online footprint elsewhere, but they feature here multiple times a week and I'm sure they know it. The titles are almost always in this mold, implying some profound yet vague discovery. Some real, recent examples:

  - "Researchers Discover the Optimal Way to Optimize"
  - "Origami Patterns Solve a Major Physics Riddle"
  - "A simple way to measure knots has come unraveled"
  - "The Hidden Math of Ocean Waves Crashes Into View"

I don't necessarily mind it, even if I don't find the articles very informative. But it's certainly fair game to nitpick this borderline-clickbait style.