You have a vastly different understanding of the cracking process than I learned from the Chemical Engineers at the engineering firm that designs thermal crackers.
Chemical engineers who design thermal crackers have a VERY limited field of view of chemistry. Think about the various polymerization processes, for instance for polyethylene. Pure pressure and temperature (VERY high), with a free radical initiator (no catalyst) in ethylene yields a polymer. A different set of conditions (in solution, with catalyst) yields a very different material. Yet another set of conditions with a slightly different catalyst yields still a third product, with vastly different properties.
The process in the article apparently is more similar to polymerization than "cracking".