Give me a break! When they signed him, they were not signing him thinking about any kind of rebuild. They were also prepared to hand over a long term contract to Bolland too.
I think you are very wrong. By all indications Shanahan knew this was not a winning team and needed to prove it to ownership. They fired their coach while he was still on a winning record in playoff contention. That is not a move of a team who thought they had a chance.
They brought in a guy who they knew was HIGHLY respected and liked around the league to help insulate and teach the youth. The price is expensive sure, but there is nothing wrong with these kind of signings for rebuilding teams. Robidas has nothing else to prove in his career.