I have stained Formica with hot blueberries. Perhaps there are some other types that do better. I tested Silestone and was unable to stain it.
Discoloration from a hot pan is not a risk with Silestone & granite although there may be certain granite sealers that may scorch. I was able to leave a smoking hot cast iron skillet on a Silestone sample with zero damage. I was also able to build a small fire with wood matches on Silestone with zero damage as a result. Thermal shock is a legimitate reason not to use non-metallic, heat resistant countertops as if they are trivets.
I encourage people to get free samples from stores and test them for themselves.
I strongly disagree, but you're entitled to your opinion. I will give Formica credit for being more scratch resistant than Corian.