As already mentioned, this sort of abnormal wear indicates an issue with alignment or a similar issue.
Don't feel bad about skipping the tire rotations. Rotations would only disguise the issue. You now know something is wrong and needs to be fixed. I feel this way about tire rotations in general. I have not done tire rotations on my cars in decades. The only issue I have had is tires wearing differently front to back. No problem. I just replace the front or back set as needed. On my truck camper the rear tires wear at twice the rate of the front tires. At about 15-20K miles, I switch out the front and rear tires. After another 15-20K I replace the rear set with new tires. Following this schedule I always have relatively new, minimally worn tires on the rear axle.