Maybe it is perception like Phier suggested. I found hunt pirate missions in each BB I checked today, and found that the pirates in USS's were piloting Asp's instead of Sidewinders and Cobras. They had about 20k bounties on them, which in the long run isn't really great but it was different. There didn't feel like any change in frequency of finding traders, smugglers, pirates etc. I've had awful runs in the past popping into 5 trader USS's in a row before. I haven't specifically gone bounty hunting today though so I never swung by any Nav Beacons or RES.
Off topic but if you haven't tried out conflict zones they are quite profitable now, if you specifically target all the big ships. Taking out Pythons and Anacondas with all your faction help is pretty easy, and the fast pace is fun. It can be a fun way to earn money in combat if you want something a bit different.