The 180 has nothing to do with a change in philosophy or the correction to an inefficiency though. It has to do with an actual change in performance on the field. 2 years ago WR's like AB, OBJ, Nuk, Julio were crushing and the next wave of dual-threat RB's hadn't really ascended yet (Bell, DJ, Gurley, Kamara)
Now those RB's have ascended and they're basically part RB/part receiver and some of the best WR's have faded due to poor QB play (OBJ, Nuk) or poor coaching in Julio's case with Shanahan gone. So that is why you have the big change in drafting philosophy, because performance has dictated it.
Another thing that no one really talks about is the 2014 draft class looked like it was easily going to be the best WR draft class of all time and a lot of those guys plateaued/faded much earlier than people thought.