Tire dry rot

Renegade has 35,500 miles. Just had the usual service done—oil change, tires rotated, fluids checked, etc. Right after that I noticed a slight shimmy in the steering wheel so I brought it to a nearby service station and all four tires had dry rot. The car never sits so that can’t be the cause. I called the dealer and they said tire warranty is 12,000 miles or one year. Really? I bought four new tires from the service station. Do I have any recourse from the dealer or Jeep?

UV is the enemy of a lot of things especially tires. Do you use tire sidewall shine? That will accelerate it. Also age is a factor. Are they original tires? How many miles on them? I usually get 4 years and 40K miles out of my tires before replacement.

Thanks for your response. The only time any shine might be used is at the “pricey” car wash which might happen twice a year. They are the original tires with 35,500 miles on them. I bought the car new in March 2016. I’m wondering if the tires had been sitting at the manufacturers before they got installed on the car. No way to tell but it’s perhaps the best explanation.