What's in it for you?

I've been musing for quite a while how so few people seem to understand the concept of doing something for someone just because you want to, with no thought of recompense, no expectation of pay back. Sometimes when people inquire on having a paranormal investigation at their home or business the "What's this cost?" question comes up, and of course there's no charge. We do because we love the field, and our compensation is getting to go into cool new places and (hopefully) capturing good, compelling evidence. Or when I send a referral to someone for a choice gig and they either view it as their birthright, or that I want something in return, neither of which is true. I do only because I choose to do, period. There is no expectation of anything in return. A thank you, or a wave from a distance would be nice, but I made the choice to do, thus it is isn't required. Then it occurred to me that perhaps these folks think that I'm angling for something in return do so because that's what they would do, that maybe they are the type to operate in that manner. Or maybe it's that cynicism has become so deeply engrained into society, that pervasive cynical thought that everybody must be out for a buck. That just may be the sad truth, that altruism is dead.