This show's overarching structure is a good example of an aristotelic episodic plot (Aristotle hated the episodic plot), which means that it doesn't contain a story arc longer than one (or two) episodes. Every episode is either a filler or hits the reset button to cancel all development.
Red John's identity is for example not surrounded with mystery but with non-information. That is of course to secure that whenever he presents himself, it doesn't violate anything (which is nothing) that's revealed about him.
But the identity has also been given so little thought that any existing character can no longer present himself as Red John without wallbangers en masse. And for a cop show: no forshadowing, no setup, no payoff... very peculia indeed.