Sorry you've had issues. That gouge in the middle of your tread is from running over something at speed. Is it cold in your part of the country? The semicircular cracks in the tread rubber below and to the left of the gouge in the second photo indicate that the tire likely hit something hard while cold and traveling at speed. Summer-only tires are not meant to be driven in temperatures below about 40-45F. They get glassy at lower temperatures and can suffer permanent damage, like yours did.
Brushing up against the curb will damage a tire if there is any irregularity in the curb, like a joint or a missing chunk in the concrete. We've torn the sidewalls on a couple tires over the years in this manner, though not on our Air yet.
Low-aspect ratio summer-only tires are the high-heels of the automotive world: nice to look at but not the most robust, nor appropriate for all circumstances.