The one in Delaware, which boasts a whopping sixteen species of reptile and amphibian, none of which are geckos? Not exactly an immediate confirmation of credibility on the subject.
And doesn't address what you were trying to accomplish... where did you see an example of dangerous practices? Who was not creating an appropriate thermal gradient? Why do you seem to think that appropriate heating is so rare, difficult or impossible?
So far you've kind of just blown a potential issue out of proportion by claiming it happens the majority of the time, and left a few inferences of anti-pet-ownership influences in your thinking. So far you mostly smell like a troll, spouting inflammatory nonsense about how horrible captive conditions are for leopard geckos.
+1