Lots of people use their minds. The people who came up with genocidal propaganda or designed the killing chambers were not exactly dumb.
You might notice that I wrote: “Peope of reason are those that capably use their mind.”
It might surprise you to ask any youngster over the age of reason (about 7 or 8 years old) if they know right from wrong.
Even at that age kids have developed a sense of justice and silently use their minds to judge people and things.
And thus it is that kids generally use their minds capably.
There are many adults, however, that have permanently rationalized their way out of ethical behavior and go along to get along — while doing wrong.