I can go outside and dig a huge hole in my yard and work really hard doing it but if no one wants me to dig that hole, they won't pay me for it. No one deserves a particular wage just because they think they should, it only matters if what they do has economic value to someone else. What I do for a living has a value to the people I provide services for. If it didn't, they wouldn't pay me and I in turn wouldn't do it and I would find something else to do. How hard one works is also typically irrelevant to the wage they receive, what instead determines the wage is the relative value of that job to the person paying you to do it because they are unable or unwilling to do it themselves. A major component of this is scarcity. The more scarce and specialized the skills required to do a job are, the more people in general are willing to pay for it. That is why doctors, CEOs, biochemists, etc. make more money than someone who works at McDonald's, even if that person flipping burgers is working really hard. Anyone can work at McDs flipping burgers but very few people have the skill set to run an organization like McDonald's in the CEO suite with nearly half a million employees, tens of thousands of locations and billions in revenue. There are a lot of factors in determining what work is worth to an employer but hard work is only one of them.
This shouldn't dissuade anyone from working hard at their job, it simply is a reminder that work in the labor market is only worth what someone will pay you for it. Teachers work for 9 months of the year and by all accounts they work pretty hard during those months but the local school board decides what that work is worth. It has no intrinsic value. If the school district thinks it is only worth $20,000/year to be a school teacher then qualified prospective teachers have to decide if they will teach for that amount. If not enough of them sign up for $20,000 the school board has to decide if they will run the school short-handed or raise the salary to attract more teachers. That is how the labor market works, or at least it is how it is supposed to work when artificial means like collective bargaining and minimum wage laws don't interfere.
Here is another example. My wife and I drove together into town today and passed a garbage truck. It used to be that garbage trucks had guys hanging off the back who picked up the cans and dumped them into the back of the truck. Kind of a stinky job but it probably paid decently. Now many garbage trucks have a mechanical arm that picks up the dumpster and angles it just right to pour the trash in the top of the truck. That arm was probably really expensive to install plus the need for dumpsters the right size and configuration for customers but the owners of trash hauling services have decided that a one time investment and on-going maintenance of the mechanical arm is more cost effective than paying a guy or two to hang on the back of the truck. That means that every garbage truck with one guy driving and a mechanical arm picking up is replacing a crew of 2 or 3 workers. Actions have consequences.
This is pretty basic stuff but in a Twitter and Facebook world many people seem unable to grasp that every economic action causes a ripple effect. ATM machines replace human tellers. Centralized order takers replace a kid in a window at McDonald's. Automated garbage can picker-uppers (that is an industry term) replace workers picking up cans. Manufacturers find ways to make stuff with automation instead of relying on expensive and often undependable workers. On and on. When we think about economics looking only at the immediate impact, we often make disastrous decisions.
So remember, work hard at your job but remember also that your job is only worth what someone else will pay you for it.