The account I just read (linked from the other thread) suggested it was more just that they happened to set really ambitious targets and make a lot of big bets

The account I just read (linked from the other thread) suggested it was more just that they happened to set really ambitious targets and make a lot of big bets in 10nm, some of which simply did not pan out. Sounds like they may have ended up in a situation where diagnostic and investigation tooling also wasn't working properly due to the use of cobalt, so they'd have ended up with fabrication failures that were then difficult to investigate, as the debugging tools also weren't working. Painful.