In my experience advocating player scripting in a MMO forum, I've observed that there is much prejudice against real life technical skills. Players seem to have less of a problem with other real life factors having an impact. Factors such as social skills or ability/willingness to spend more time on the game. I think this is because it takes technical skills to evaluate the true impact of mechanics involving technical skills, in order to come to the conclusion that they are mostly benign.

OTOH, I've also observed that some nontechnical people actually like scriptability and others can be convinced (with some difficulty; they often assume you're trying to skew the game towards your abilities for the sake of getting an edge) if you have the chance. And of course, people that can program absolutely love the feature. Unless you start with millions and a recognized IP, I think your best bet is making some underserved audience love your game rather than try to please the mainstream.

So I was playing devil's advocate here. As I said, I myself would love player scripting, and if I was to make a MMO, I'd bite the bullet. But whatever you do, I think these are factors to take into account.