Sorry I forgot there was any confusion. The more worn tire was on the front from mile 0-5000, and on the rear from 5001-6600, while the less worn tire was on the rear from mile 0-5000, and the front from 5001-6600. The pairs of tires (front and back) have worn evenly. I would've expected the set of 4 to be more even considering I rotated at 5000, a normal interval.
I think I understand. Now I am not trying to insult you. I am seriously trying to help. But did you rotate your tires by moving them in a circle? Like LF to RF; RF to RR; RR to LR; and LR to LF? If that is what you did, the wear you are experiencing is normal.
Rotating tires means moving the 2 front tires to the rear and the 2 rear tires to the front. Someone correct me if I am wrong, but those OEM Goodyears look symmetrical to me. That means they can be mounted on the left side or right side of the car. You rotate symmetrical tires by either moving the LF to RR; RF to LR; LR to LF; and RR to RF; or you can do LF to LR; LR to LF; RF to RR; and RR to RF.
Directional tires must always stay on the same side of the car. So you rotate directionals LF to LR; LR to LF; RF to RR; and RR to RF.
FWD cars wear out front tires twice as fast as the rears. FWD cars have more weight over the front and are the driven wheels. Drive wheels always wear out tires more quickly and having more weight over the front only hastens the wear.
I'm surprised people are saying they replaced pairs of tires though. The point of rotating them is so that the wear evenly as a set of 4. Am I missing something?
Nope. You got it. In theory, rotating tires evens out the wear and helps you get more miles out of the tires. It is better to have 4 of the same tires for handling. To use an extreme example, imagine driving your car with winter tires on the front and summers on the rear. The car will fishtail all over the road in the snow and will badly understeer in the summer.