Ironically, by fighting Blackwell and then Doran, Junior actually moved himself ahead of Jacobs in terms of positioning for a potential Golovkin fight for the real belt(s). Brook ended up getting the date, but Jacobs only got his shot after Brook, so the route Junior took did make sense from a business point of view. His old man was just impossible to negotiate with. I agree though, Jacobs beats that version of Eubank pretty comfortably, and Golovkin would have likely ended his career, so in the end it was the correct decision. It just left him in the wilderness until the Super Six tournament, where once again he found his level. Also agree that he got out of jail with Korobov, which always seemed a strange fight to take at the time – low reward, high risk.
When he started he looked like Euro+level who'd get a shot at higher because of his name. That's what happened.