Remy you have some interesting points about Allen Robinson. If I'm honest, I too felt that aside from that one year of crazy numbers, he seemed to me like a very good technician but wasn't particularly explosive. Interestingly, taking a look at the 2016 separation stats, former Bears Eddie Royal and Martellus Bennett rank pretty high on that list. Then further down the line you have someone like Larry Fitzgerald, in the upper-echelon of wide-receivers who isn't known (nor never has been known) for horizontal separation and yet was always dangerous.
Even in this season's high-flying KC offense, they don't have any receivers in the top-10 on the separation list (though Tyreek Hill has been there in the past). Separation as a receiver is certainly important, but other things are as well, things like savvy, reliability, consistency, predictability, and football IQ. Brandon Marshall is one that I can think of that possessed these talents in his prime (but unfortunately dropped too many passes and then became a team detriment once he felt like the team wasn't competing up to their potential).
I've maintained all along that Allen Robinson was still injured and wouldn't reach his full potential until next year, and I still feel that way. This offense will break-out next year, and I believe Allen Robinson will be one of the top receivers in the league.