I have six Maxxis ST tires on my 5th wheel. They were the best of all the ST tire brands out there when I bought them a few years ago, and they have proven so far to be as good as I hoped. But that said, I also run a TPMS so I always keep tabs on their air pressure and temperature as I tow. Plus, I ALWAYS keep them at maximum air pressure (80 psi), and I have E rated tires which have a combined rating far more than the trailer weight, and I try to never let my trailer set longer than about 3-4 month without moving it and exercising the tires.
But more common than not people tend to either let their trailers sit seemingly forever without moving or using them (sometimes up to a year or more between uses) while the tires just sit there drying out from lack of use, and/or they run them too low of air pressure not paying attention or thinking that they're softening the trailers ride, and/or they run too light of a tire rating for cost reasons or dont know, and/or they grossly overload their trailer. Then they have tire problems and blame everything else but the potential real reason.
Thats not even accounting for other variables like out of alignment trailer axles, or dragging trailer brakes causing heat buildup, or not balancing their trailer tires because "its a trailer" as their trailer tires go bouncing down the roadways generating heat eventually having problems.
So in point, yes there are plenty of negative ST tire threads out there, but if you read all the way through there's generally a reason why besides the common talk about how bad ST tires are. Also to point out is that ST tires are not built the same as LT tires. ST tires dont have reserve capacities because they're not rated for carrying passengers, and are made for lateral support only. So yes, LT tires will outlast any ST tire simply because they're built to different standards. But thats not to say an ST tire isnt going to last if taken care of.
Just to mention too, I've had ST tires on a flat bed trailer last over 10 years. I use the trailer all the time too and I attribute the longevity of those tires to the fact that they were used often. And I have another trailer with the same tires which I bought at the same time. Yet that trailer sits all the time and guess what.....the tires didnt last. Want your trailer tires to last then DONT let your trailer sit unused.....