Pretty simple ,he was called in to save the job of a coach who hadn't "gotten it done" he took what he was given there and here. As far as not caring about o-line, Martz wasn't the incompetent GM who let Fred Miller walk,nor the incompetent Dr. who said Kyle Turley's back was OK, and every scout under heaven thought Alex Barron was the real deal.
AND OBTW the he didn't care about defense is just SOOOO MUCH BS ,he gave Lovey every first rounder he wanted ,Arch,Pickett,Thomas,Kenedy,Lewis ,THINK what he could have done with the GSOT with those picks for O.
Simply put when they got rid of Martz it was a case of finding THE MOST competent man in the org. and fire his ass.
If Shaw and Ziggy had been as good at their jobs as Martz was at his,no Linny ,no Spags,Kroenke wouldn't have been anxious to buy at the price the franchise would have commanded.