HelloCustomer This could very well be an alignment issue! The toe is the adjustment made to point the tires, they could both be pointing in or out. It is recomended that you align the car every 15k or so. Another factor is tire pressures, maintaining proper tire pressure assures even wear on the tires. Driving conditions and habits are the biggest factor, if you do a lot of city driving where you are turning a lot, or high speed cornering also contribute to tire wear. But remember, you are having them rotated for this same reason, tires left on the front will wear out sometimes 2 or 3 times as fast as the rears! The final factor is the tires themselves. You get what you pay for!
That 65000 mile warranty doesnt mean they will last that long, onlt that if they do, they will not have a defect in that time. The only other thing that can cause poor wear would be bad struts, but even then the tires would likely be rough.