Unfortunately, many fighters do this to protect themselves not only from good body-shots but, also more diligent training. A universal belt line rule. This will allow for fighters to throw legitimate body shots without fear of disqualification. It also forces the less diligent boxer to focus on his training. Again this puts more pressure on the fighters to concentrate on their training regimen.
Training is almost always what separates a winner from a loser.
It is somewhat surprising that in this day of cable television and satellite TV that the sport of boxing has very few television venues. PPV has completely ruined boxing's fan base. It is because of PPV that many children dream about growing up to be some hillbilly clown in tights, with a raspy voice flying from ringposts instead of dreaming of growing up to be the next Joe Louis or Sugar Ray Robinson. Even the most rabid boxing fan hesitates to pay forty bucks to watch the Michelin Tire Man attempt to pound on somebody who once held the title for three days. This continued until the mid 1960's.