Long time lurker, I had to chime in...
I think AMartinez is a very good athlete and could be a decent QB is a conference that plays his style of ball. Granting the QB lots of space like the PAC12 or BIG12. I like the kid, let me make that clear.
His main issue IMHO is that his anticipation and accuracy are poor. He has always overthrown receivers and missed easy tosses. He misses more "layup" passes than almost any QB I can remember. I mean simple swing, slant, and go routes are literally an opportunity for interceptions or at best drive killing poor passes.
At this point, I'm not sure if the Huskers have anyone better but I think the team knows that Martinez minus a massive Oline upgrade in performance has most likely reached his apex, in 2018.
The other elephant in the room to me is the offensive philosophy which goes pistol/shotgun on the goal line with no lead blocker, but that prolly is a different topic...