The market adjustement on Gatewood wasn't something I came up with. This was the kind of analysis given by people who spend a hell of a lot more time analyzing these things than I do. The feeling being that in previous drafts, a guy like Gatewood is a mid first rounder. That being said I agree with what everyone seems to be saying. It's hard to ever say definitely that a skill or skill set is truly overrated or underrated in the draft. You can be right or wrong about all kinds of guys.
Maybe Gatewood become a future superstar and then people will be kicking themselves for letting him slide. I think you do see the market adjust and react to these sorts of things but whether that means these adjustments actually lead to an improvement in the overall quality of evalution is not at all clear. It's an imperfect science to say the least. The whole process can actually seem entirely luck driven and the preparation futile but you can bet that no team is just going to throw up its arms, everyone's trying to refine this process and that, productively or not, creates trends. The fact that there is a correspondence between draft position and MLB track record suggests that at least overall there's some method within the madness and that at least in a broad sense, teams know what they're doing.