I don’t think it’s anything to do with summer jumping, we’ve always had that in Ireland and the type of horse running in them tends to be different to the winter horses. A 3 month break would be very unfair on horses who like to hear their hooves rattle off the ground.
I do think breeding has a lot to do with it. I’ve only been following racing for around 30 years but I don’t ever remember as many horses breaking down on the flat as there is now, and back in the 80s they often ran on very firm and even hard ground. Maybe the stats will prove me wrong and it’s just the fact that all races are now on tv, but it just seems so bad especially in the last couple of years. Owners don’t seem to have the patience to wait for the old store horse type in NH and there’s been a huge influx of flat breeding into it. As for the flat, I’ve never been a fan of 2yo racing. Some of the 2yos I’ve seen at the races this year look more like ponies.
I don’t know what can be done to change things but I do hope something is done or we risk turning into the killing fields of US dirt racing.