Milk was a bad choice.
Boots are like cars. If they were built to last a lifetime, they would cost 100 times more and the companies would lose money in the end.
I feel like companies build boots to last 3 to 4 years for the "average" snowboarder... someone who rides about 20 to 25 times a season (and probably isn't putting in full 8 to 4 PM days every time).
Also if the boots aren't meshing with the bindings well, I would expect some ware in specific areas, especially if you aren't someone who straps in really tight. After only 15 days though... something is missing from this story...