It may just be that he is the low cat on the totem pole.. I think in every household with cats you have an established pecking order. Every so often it may change or a cat will challenge it. We have some pretty clear barriers here, and a few challenge it once in awhile. For example.. Zakk is top cat, but Rocky is always antagonizing him into a wrestling match until it gets nasty.. no blood or anything but it gets pretty loud.. Rocky dominates the younger two, but when Rocky wants attention from me.. suddenly Cookie is there to steal the thunder. He also tries to wrestle with Rocky but he really isn't a challenge to Rocky and Rocky usually ends up holding him down, alternately licking his head and kicking him..
If you feel one cat is missing out, you could try getting another scratcher.. We have four cat beds so someone always has a place to sleep and no one has to fight.