That's a great link and a real pattern. A lot of the sites I scanned had exactly this problem buried underneath the surface issues. The technical signals (missing sitemap, no structured data) are easy to flag, but the reason those things are broken in the first place is often that someone reorganized the site, swapped CMSes, or "cleaned up" the URL structure without redirects.

The tool catches the symptoms. The TBL article explains why those symptoms keep showing up.