While I do agree that some things we sell on board are rubbish I think as crew we attain lets say, higher expectations than the average charter pax.
Personally I enjoy inflight sales a lot and do all I can to sell as much as possible. A couple of years back my company started selling toe rings, much to the disgust of the crew, but after a few weeks they had sold out, they practically walked off the aircraft and still do. We might think this stuff is rubbish, but hey it sells! If it makes money for the airline and commision for they crew and the passenger is satisfied with their purchase then give me more rubbish to sell!