I don’t want to be a shadchan for the following reasons but I do agree that they should get paid.
I think the problem is that people are comparing shadchanim to plumbers when they are actually much more similar to therapists. Not everyone can be a shadchan. It takes a lot more effort than just throwing two names together. To be a shadchan, one needs to have a certain understanding of human nature and of what personality types go together. They have to have guts to redt the shidduch (because there is always the risk that both sides will be mad at them) and they have to have the right level of persuasion to help the couple make the best decision. Most frequently, the one who makes the big bucks is not the one who casually mentions the name to one of the mothers at a simcha; that person usually gets something not much more expensive than a candy tray or some flowers. The one who gets a respectable sum is the one who is on call almost 24 hrs a day for the 2+ weeks from the time the names are redt until the couple gets engaged. However, the 24hr/day job, most frequently, does not get compensation if the shidduch falls through, even if the couple called them 5 times a day for a month.
Being the shadchan is the most important part of the wedding and takes as much skill and much more time as does everything else involved in preparing the wedding. It seems like less work, however if you factor in the time the shadchan put in, as well as putting her/his reputation on the line, the shadchan actually put forth a lot more effort than did anyone other service for the wedding.
It actually is also similar to a babysitter, because first of all, it is a chessed that costs money and second that it is something you can do yourself but it is a massive convenience. The fact that the teenage girl is getting paid does not make it any less of a chessed when was willing to babysit for you despite that she had piles of homework and tests to study for. If you want to use the service, it costs money. No one is chaining you to do the service but the service will cost the provider time, money and aggravation and they deserve compensation.
It is a hard job, it is a time consuming job and it would be an extremely rewarding job if people didn’t compare them to thieving plumbers.