Hi all,
Personally, I think the thing that holds people back the most is fear.
I don’t think this is particular to game-making. Fear seems to be what stops most people from doing anything creative.
I do a lot of work with people in all ranges of creative endeavors (eg: painting, writing, music composition, etc.) and what I hear most is that people are just afraid that nobody is going to like it. Of course, as mentioned above, harsh and oftentimes hateful criticism that saturates forum-space can often lead a person to stop creating altogether, since they consider these forum members not only their peers, but possibly their support system as well.
Sure, learning to program from scratch can be a daunting task for anybody, regardless of how intelligent they may be. But there are so many game engines out there (GameSalad for example) that make the bulk of game generation more of an artistic challenge, rather than a programming one.
My favorite way (and from my experience, the most effective way) to get people to be more creative, is to get them to just let go. I know it sounds like a hippie-driven philosophy, but there’s so much to be said for getting people to just let go of their fears, have no expectations, and just live in the moment of creation.