Personnel is Policy vs. Wages

 You can try to pay someone higher wages to incentivize better work, but this is unlikely to be effective. It's the same person, so you will get the same policy. You've simply made the policy more expensive. Insofar as grass monkeys learn from their mistakes, they have already learned everything they're going to. By the time you hire someone, they've already made every mistake they're going to make. Any mistake they're still making is a mistake they'll make forever. See also: net worth is a genetic trait.

 To get better work for higher wages, you have to get rid of the lower-wage person and hire a higher-wage person. Low offered wages select for bad workers, not bad work. Of course, these low-wage workers will hardly stop themselves from applying for high-wage positions, but you can reject them as you will also get high-wage applicants. On this side, the selection needs to be on your end. It's probably fine to blithely pick the highest-status applicant, regardless of skills & experience. 

 On the wagie side, consider that employers only need to offer a higher wage if they accidentally hired a more-competent-than-expected worker. They need to offer a higher wage because he can command a higher wage. Thus, your argument for getting a raise should always and exclusively be, "I will quit if I don't get a raise." If you don't think you can command a higher price elsewhere, then they have no reason to give you a raise. No wonder you have so much trouble asking for one.

 I think the logic here is fun. Assume they're not appreciating the work properly. Then the worker ought to quit for lack of appreciation, and find someone who offers better. (Revenge is Sour: they're not going to learn better, just quit.) Now, assume they are appreciating the work properly, but the worker still doesn't feel appreciated. Then the worker ought to quit, to save the company from dealing with a crazy worker. Due to this converging fork, the substance of appreciation is irrelevant; the worker's perception alone fully determines the correct course of action.