I think lumping criminals into one category is kind of simplistic.
There aren't a lot of smart criminals, because smart people can figure out how to make money without the danger of getting killed or incarcerated, but there are some.
Smart criminals don't usually get caught. An LEO I know once commented that there were definitely criminals operating in the jurisdiction that they were aware of (via MO and committed crimes) that the all officers in the department knew they would never catch.
The problem is that studies on criminals are usually based on criminals that have been apprehended/convicted/imprisoned. That tends to bias the study results toward the "dumb criminal" side of the book. It's a mistake to fall into the trap of believing they're all dumb.