I guess the key is how often are we just handed a spec and asked to code it up. In my roles, I've never worked like that, I've nearly always had some impact on

I guess the key is how often are we just handed a spec and asked to code it up. In my roles, I've never worked like that, I've nearly always had some impact on design - but hey, that's just my experiences. I would agree with your original point though, that domain knowledge can be learned quickly by a good hacker. Which leads to a more interesting question; what techniques can we use to learn a new domain?