It's not a matter of being "too dumb", it's a matter of having the economic means to get one, to take time out of your menial job to spend all day at the DMV to get an up to date license.
I recently had to update my wife's DL, to both reflect her new address and her new last name. It took two trips down to the DMV, and getting an on-line appointment was like playing the lottery. We eventually ended up having to drive 25 miles to another suburb because the location in our town never has open appointments.
Racist Douchenoodle say what?
This is the same logic that old-timey segregationists used to use to justify poll taxes and literacy tests. Why am I not surprised?