So Red John was an old sheriff from a little California county.
He eluded FBI, CBI, Homeland Security for like twenty years and killed a lot of people gruesome ways for no reasons.
He erased the memory from witnesses, he entered the main character head to know what he thought, he hold in hand the entire Visualize cult and even a corrupted group of a thousand of law enforcers, who never tried to stop him in some way.
He mastered the use of poisons and sharp weapons.
He knew how to enter in the encrypted data bank of a federal agency not letting traces whatsoever, so he was also a top notch hacker.
He was a womanizer and was so charming that all the women in the series gave an altered description of him, because they looked at him through the eyes of love.
He never made a mistake because was a genius.
He was worshipped by a lot of disciples who constantly choose to die instead of talking to the police, because he was feared more than death.
He had a lot of resources, and was probably filthy rich.
He never shook hand with Patrick Jane for what I can remember, nonetheless he was included in a list near the big bosses of two governament agencies, the leader of a religion, two low class goons and a forensic expert, showing how clear was the vision of the aforementioned mentalist.


...


It makes perfect sense to me.