I often hear leaders telling me how so and so on their team has a bad attitude but is otherwise great at the job so they see no reason to address the bad attitude.  If the performance is good, you can live with a bad attitude, they tell me.  This acceptance is wrongheaded.  In time, a bad attitude, if it persists, will affect performance.  The performer begins to work only for a paycheck.  Excellence ceases to be a goal.  Performance begins to suffer.  A bad attitude is a precursor to bad performance; it is bad performance.