“Is it disturbing that your son’s Rebbe gets paid for teaching your kid Torah?”
I might (didnt really think it through) agree with the sentiment, but, this is a poor analogy (and not just this specific example). The Rebbe gets a salary from the yeshiva regardless of if, or how much tuition a parent pays the yeshiva or how much classroom time or out of classroom time he puts into an individual student or how successful a student is. Is the shadchan getting paid for all efforts expended, successful or not?