I don't see why being the show runner means he can't state his own opinions on it, fans do it all the time, quite often in a far more personal way. I can't believe that there is a single DW fan who is completely happy with every single episode made, so why should Moff be?! I don't want someone running the show who isn't truthful, I like to hear his opinions as much as I like reading and discussing fan ones on forums.
Also have never understood this aimed at/appeals to thing either, does it really matter how old you are when you watch it. You either like it or you don't. Personally when I watch it I enjoy feeling like a child and being taken in by the magic of it. The (almost obsessive way) I rewatch episodes are usually done in a 'family setting' (where I'm explaining things to the kids that they don't get and discussing the morals being presented to them) or with other adults or by myself where I'm discussing it at that level. I can't say it's aimed at my ages group due to the material, but it makes no difference to how I see the show