I think there might be some designers who would want to build up a portfolio and offer their services for free at the start. That's not really a bad idea but it can't last if they want to do it as a business.
It could also be that there are barters being done with the graphic for free if the receiving party offers some other service that they're in need of for return.
I do graphics for free for close friends and family but that's because I feel bad if I charge them.