I am quite wedded to the view that epistemologists should concern themselves with knowledge rather than our concept of knowledge. The analogy I like to draw here is with our understanding of (other) natural kinds.
Chemists in earlier centuries were quite interested in the nature of acids. They had no interest in analysing their concept of acid. After all, they knew that their understanding of acids was at a fairly primitive level, and what they wanted to do was understand something about the world better - the nature of acidity - not something about their own concepts.
