On your bold point at the end, what difference does it make if I talk about the "theories" of "ought" or "good" instead of the "concepts" of "ought" or "good?" I actually do often talk in terms of "theories" myself (perhaps a result of the science fanboy tendencies analytic philosophers like myself often have), but it's not obvious to me how important this is. When I read other philosophers who prefer to talk of "concepts," I usually assume they mean theories too, and usually what they say makes sense when so interpreted. I suppose confusing theories with prototypes or exemplars might lead to over-estimating the importance of intuitive examples and counter-examples, but while I do think many philosophers often do that, there are many other reasons they might make that mistake. Or were you thinking of other possible effects of the confusion?