What I don't understand is why Goodyear allowed poor Chinese quality control ruin their name
Goodyear had the same ST problems before made in china ST tire hit the streets or even RV.net. They were made in the usa as all ST tires were by the major tire companies back then.
Goodyear did have serious issues with the Marathon. Finally they redid the tire and gave it a circle S molded in the sidewall. Good improvement.
Most lasted 8k-10k (vs 3k-5k ) before separation issues popped up on trailers that spent most of their time and life on the road. For most RVers/utility trailers/lawn mowers trailers/etc they worked fine as most RVers tire life are spent sitting around/short trips/a few trips a year/etc.
Some time after that Goodyear sent the ST tires out of the US.
Most of the other major USA tire companies had slowly dumped their ST line completely. ST tires were simply a small niche market tire.