I don't care who red john is, it's been 6 years and i have nothing but good memories for this show, every monday i couldn't wait to get out of my crappy school to download and watch new episodes.
So stop complaining that Bruno Heller wasted your time,you haven't even seen the red john episode, if you have a theory i'd be happy to read it. Otherwise, stop judging until you see the actual episode. 

Btw, the saddest moment in the show for me is S5E02 at the end, when Jane locked himself in the attic to drink the tea that gave him hallucination , so that he could see his daughter again. An imaginary daughter, i just hope he stabs red john or somehow makes him suffer. 
That's the only thing i would prefer , that he doesn't kill him with a gun like I saw in the promo.