Yes people can become discouraged, and quite easily too because they're putting time and effort into the project and they want some acknowledgement that what they're doing is good, and will be successful. I think it presents a challenge that needs to be faced, because only by being shown and understanding what is and isn't working will you be able to improve them.
So those who show early stuff about their fan project are risking their ability to continue through with it, and some continue and learn from their mistakes and others give up.
There's a project I'm working on at the moment but I haven't posted details about it anywhere on the net, and I'm not going to here. Its only because I want to make sure I have something finished and to show for before getting a critique on it.