Is it possible they'd just like some non-combat encounters?

Or maybe even just more RP time?

6 encounters in a session seems a very fast pace, unless your sessions are 12 hours long. My sessions are a bit on the short side (3 hours of actual play, plus time spent on greetings, breaks, pizza ordering, etc), but actually completing 2 entire combat encounters in a single session is pretty rare for us once we get past 5th level or so.