This time of year a lot of courses start to wind down their operations. One of the items that gets skipped is raking the bunkers in the morning. Eventually they bring in the rakes and the bunkers become more natural, filled with various hoove and foot prints.
When there is no rake, I generally try to scuff out and smooth over my foot prints and "divot" hole. A lot of others appear to just play out and move on. I guess I can see both sides. My efforts make the next player's shot slightly easier if they happen to hit into the exact spot. With the rest of the bunker a mess, however, my scuffing the sand doesn't make a whole lot of difference.