I think Mark is really passionate about Runescape, and he wants to see it succeed, which is why he hasn't chosen to move to another game.

I think a role like Head of Runescape is always going to be a tricky one to place with the right person because the ideal person needs to both be fully invested in the game and understand its culture and merits and whats good for the game and even understand the design process eg a bit creative but they also need to know the business side of things. Mark would not doubt make a brilliant HoR in terms of giving us amazing content, but I can't see him doing the business any favours where as people that are uber business like that ex-paypal guy who came before MMG don't understand the game at all and enforce choices that are brilliant in a purely hypothetical business model but awful in an actual game.

That's why we lost Andrew, he hated all the business stuff, he just wanted to create a game and enjoy that experience.

Personally I want Mark to stay on his post, so he could still give 100% to create content, instead of dealing with all the other stuff as well.