Re: Please tell me I'm overreacting...
You are not over-reacting, but I can feel your pain and frustration. Any of driving in the Midwest have to face the fact that the roads are in terrible shape from mid-winter to late spring, when the road crews finally patch them. I94 is especially crappy due to all the truck traffic. I spend most of my driving swerving across my lane avoiding chewed up pavement and pot holes. At least it keeps me awake on long drives.
I have 17" on my Audi and have replaced two tires after hitting pot holes -- fortunately the rims were not damaged. This is my winter driver, so it sees the worst roads.
My two XFs are only out in the summer and therefore are spared the worst of the roads. As far as I can tell, both have good rims and surprisingly, good rubber. I think I have enough rear tread on my roadster (currently 32k miles) to get through this summer and the fronts are maybe 1/2 worn.
I doubt it was a manufacturing defect -- just bad luck in hitting a pothole or bad expansion joint the wrong way at high speed. Good luck.