You're entitled to your opinions, but this statement is contradicted by facts. I've seen and experienced many cases where a thorn or other piece of debris was removed from a high pressure tire, and it sealed right up. I've also seen many cases where a tire sealed after losing 30-40 psi and could be pumped up and ridden as if nothing happened. Finally there have been cases where a tire was completely flat, was pumped up, went flat again, and after three or four tries held air and was good as new after that. So use them, don't use them, like them or not, but don't say sealant doesn't work for high pressure road tires.