Its funny how we give Sean Cunningham so much credit for the series, when it was actually his idea to 'get that mask off of Jason' when it came to Part 9. It was one of the first things he wanted to do with Part 9 when he came back to the series.
I've always felt he was a mark for his original film and that's it. Publicly, he'll take the praise and accolades about how far the Friday the 13th has gone, along with all the money he's made from it, mostly on the back of Jason himself. Privately, I think he only really likes his original film and just assume dismisses Jason in private. Just assumption of course, not actual fact talking there. Which is also fine by the way. I've seen plenty of opinions over the years of people who prefer the original film and Pamela over any entry with Jason. Its just an opinion, everybody is entitled to what films in the series they like.
Not to be a negative nancy, but im actually quite surprised he gave the Devs the license to make the new F13 game. You figure by now, he doesn't care about the money, but I guess I'm wrong or maybe he really only cares about the money. Maybe im wrong, maybe him giving the license to the series is a way of him giving back to the fans. Hell maybe im wrong about Sean being a Jason hater. Its just this developing opinion I've got for the guy over the years.
I don't think Sean loves Jason the way John Carpenter (well more Moustapha Akkad) loved Michael Myers or Wes Craven loved Freddy.