It depends on your definition of interested. If being interested means getting the job, then you're right, no one was interested. But him not getting the job, which would make him think he was sitting the year out since there is no guarantee for a midseason firing, does not mean that no one would touch him with a ten foot pole. He easily could have gotten interviews with teams but had a case where they liked whoever they hired more for their team. Simply being interested in someone and eventually choosing them out of a field of applicants is not one in the same, so several teams could have been interested and simply found out they liked their guy better. We know he didn't get a job that summer, but we don't know that everyone immediately brushed him off. He easily could have gotten a long look before the team decided they wanted to go a different direction.
Also, on the point cup contenders wouldn't want him, most cup contenders don't fire their coach the season before unless they win due to some miraculous event/ offseason move, the team extremely underperformed the year prior, or everyone despised the coach, so before the season started/ during those first four games I doubt a team like Pittsburgh that year or LA in 2012 thought they'd fire their coach midseason.