They did.
They needed a LT - they drafted Fuaga
They needed a RT - they converted their former 1st round LT to RT.
They needed a TE - They've added two developmentals
They needed a 3rd/4th WR to compete with Perry they signed one in FA.
They needed a better scheme - They brought in Kubiak
They needed anothe weapon - They've committed to using Taysom more than the previous staff
They attacked everything they could, not enough time has passed to say whether or not it was enough. That in itself is the fallacy in your opinion...we don't truly know yet. Everything is speculation to this point.