Tying teachers pay to performance

So i read about this controversy in Canada, and i reflected as an educator here in HK, why don't we push for the same thing? Having studied in HK's education system as well as teaching in it, I can say that i've seen the discrepancy in teachers as well as how unproportional the salary scale is. The point system just goes up as you continue your contract with the school, and let's be fair, when do you really hear a teacher being fired? Unless they really eff up. So basically the older you are you have a fatter salary. So you could have a teacher who really sucks at teaching, no one gets what they are teaching and they aren't making an effort, staying in the system and getting paid shit loads. Whereas there can be hardworking, lets not say fresh grads but 30,40 year olds working there ass off and providing quality education but is scraping half of what the oldies are getting. 

Don't get me wrong it can be vice versa but that absolutely explains why we should have some sort of merit system. To enforce the quality of teaching on every level. This will also attract people into the industry. If they get the incentive to teach, and be able to make a living, no one would have asked Taylor Mali "How much do you make?(as a teacher)" because lets be honest, other than making a difference, a bit of monetary incentive would be nice.