I'm not sure if I agree that a tire has "failed" when it wears out.
In general you can place a tire's condition in 4 catigories.
1. Normal wear with no structural or external conditions. This ranges from new to 100% worn across the tread surface.
2. Wear related - This is usually what happens with improper alignment although extreme agressive driving can contribute to conditions such as center or shoulder wear.
3. Service related - Cuts, punctures, Impacts, rapid or shoulder wear due to improper inflation and /or alignment, delamination ( separation) due to improper inflation/speed for the load.
4. Manufacturing related - usually the result of some form of contamination during the manufacturing process such as non-specified material being built and cured into or onto the tire ( paper, nuts & bolts, wire, bits of rubber, general trash) Plant cleanliness is a constant problem especially when you consider that the uncured rubber is sticky and seems to attract almost any form of dirt.
I consider a tire to have "failed" when it doesn't deliver the life or performance expected when purchased, but in this case "failure" does not identify root cause which could be any of the above 4 catigories.