I am a weird person who thinks that money paid for something is equivalent to the amount a person thinks something is worth, and because this whole topic is about subjective values versus salary, my funky world-view should work fine. (This is not randomly self-deprecating, stock market people anger and confuse me, generating wealth from no contribution to society*)
If you think about the relative scale of the contributions that the individuals in our society make from this "how much is it worth"x"how many people benefit" value, it begins to make more sense that people performing tasks that seem trivial for lots of people would make more than those who provide services that are inarguably essential for a limited group.
Let us look for example at a teacher, a component in the education of children (a resource which I am told is precious), in a school with six class periods this teacher might provide a sixth of the instruction for thiry-five students per class. Imagining that this teacher is overworked (a stretch, I know) and teaches six classes per day, that should mean that she is entitled to the tuition of 35 full students, right? Sadly, this quantity is greatly diminished by the cost of having a school to teach in, not having to wax the classroom floor, getting new computers every decade, and paying the salaries of the support personnel such as principals and secretaries. Once you factor all that in, you realize that there are a large number of people contributing to the education of these hypothetical students that all need to be compensated for their work. So even though the market might put a very high value on the education of children, it gets split up out of necessity and teachers end up with a pittance.
Don't even get me started on what I imagine the economics of rescuing kittens from trees is like.
Let us consider the athlete thing. They provide their services to a huge number of people. Even if they are doing something that is worth $0.10 to the average person, like catching a ball and running to one end of a field in conjunction with other people working towards the same goal, that times the tens of millions of people that benefit from this entertainment means that they actually have a greater impact on society by orders of magnitude (if how much things are worth to how many people is our yard stick) while providing very little value to the individual. Of course, their efforts probably cost the viewer more than $0.10 to observe. Indeed, I am acquainted with several people who pay dozens of United States Dollars every single month for the privilege of watching these athletes display their skill.
To succinctly sum up my drunken ramblings, deliver crap to lots of people, and you will probably end up with more money than saving the lives of anyone you can help.
*: Aside from their self-imposed exile to financial districts. The benefit of which is diminished by the fact that they still come into contact with people who work for banks who do provide useful services and must suffer their existence.