I am sure Tate Martell is a wonderful player and he will do well with whichever team he finally ends up with. I just don't see a point to offering another 2017 QB when the one that is committed is going to enroll early and is peer recruiting other players to joining him in Lincoln.
Add that to the fact we have a QB from 2016 that enrolled early and a transfer from Tulane and things can get very murky at that position and create unnecessary drama for an already overly dramatic fan base.
It appears to me that the coaches believe in their abilities to land a very good QB each class and that, in turn will give them the options that they need. If one of those QB's happen to leave before their eligibility is up in Lincoln, I could see the coaches trying to get 2 in a class. But for now, it's 1 per class.