It all seems to be getting almost elitist in some ways, people used to pretty much always post their fandom related works publicly when I first joined LJ, and these days there are probably more locked icon communities than there are open ones. And if people really do want to post their work privately then I can respect that, but it usually seems to be a case of having locked communitities as a way of getting as many members as possible to join your comms. People have locked communities at the same time as pimping every new icon batch they make at all the public comms, and "join to see". Although I know that the GG general icon community came up with rules on don't link locked posts, so now the "it's being locked in three days" posts are more common