This is non-sense. There's no rule that says collectively bargained contracts can't include rewards or incentives for higher-performance. In fact, many do.
Look at any professional sports contract. Players usually get bonuses for hitting predetermined stat goals on the field. Look at any teacher contract. Teachers get bonuses for attaining higher education and certifications, or simply taking on leadership roles.
Look at any professional sports contract. Players usually get bonuses for hitting predetermined stat goals on the field. Look at any teacher contract. Teachers get bonuses for attaining higher education and certifications, or simply taking on leadership roles.