Assuming Gin is innocent, the Mafia could save him to buy them another lynch of a stronger player as well as buy more time in general.

I share your sentiments on Yoru. However, I still think Gin is the most logical target. He has done a very poor job of defending himself, as well as those that continually try to prevent his lynch. The deaths of Ichigo and Soifon proved very beneficial for that group in general. I don't want to play int the Mafia's hands if I'm wrong, but this sleepy game is certainly not pointing to any other singificant threats.

One must also consider his voting history. All of his votes were non-mafia roles, none of which he contributed any evidence in and generally joining bandwagons. He even changed his vote from Soifon to Aizen to create a tie, in which Jin, who has been defending him recently, hopped on at the chance, again with no logic of his own.