I guess there is still someone on the planet who isn't praising the Bills for that trade. It has been an extremely successful trade.
You can trade up for whatever receiver you want. None of them are as good as Diggs. Diggs is a proven number 1. All those rookies are just rookies, and some of them will be busts.
And what are you taking about with contract length? Rookies are had for 4 years, 5 if you use the 5th year option. Diggs is under contract for 4 years. That's essentially the same length as a rookie contract.
If you don't think the trade for Diggs is a clear win, you are just an idiot. Homerism has nothing to do with it. Everyone outside of the organization has been praising the trade.