Man I cant believe you don't rotate your tires. Every person I have ever known has had to rotate or the tires would look something awful.
I rotate and balance them I just wait until they need it. These just happen to have gone a lot longer than normal before they needed it. They barely show a little more rounded shoulder on the front now. Still ride smooth, I doubt they even change the balance weights. Before these I ran BFG's for a long time and usually had to rotate and balance every 6-8k miles. That was even with the good ones before they changed them to the soft ones that wore out faster. I have never had to rotate any tire more often than that, even the crappy Goodyears that came on my truck.