NEW YORK - Jockeys often seem bewildered that they don't get more support for the issues they care about from horsemen and racing fans. Perhaps they should consider how selfish and unsympathetic their leaders sometimes make them appear to the owners, trainers, and horseplayers who provide their livelihood. Two recent incidents, a walkout at Aqueduct on Feb. 3 and an ongoing suit in northern California, are cases in point.