I take your point. I have always assumed that the EW is a bit like the Apple App Store in that it is a guarantee that the extension is safe and works. But maybe even the App Store doe not provide the guarantee of kosherness (does that word exist? - Ed) I assume?
I have further assumed that extensions on Sketchucation could be a bit dodgier. I think it must be quite confusing for newbies to be presented with two completely separate platforms for these things. I am sure there is a good reason why developers choose one over the other, but still.