Once something is out there, you can never take it back.
Having public work means you can get direct feedback on the work you are doing and this is an excellent way of learning :)
Edit: Your comment reminds me of over-hearing a man make fun of another man who had asked a question in a forum. The irony of this was that he was sitting in the corner of a dark, smoky bar at night while making fun of another man who had the balls to ask a question in a public forum during the light of day. No one knows the guy who was making fun because he himself was too afraid to ask questions and always thought that someone like himself would criticize him as he criticized others. Technology could use less negative egos!
However, I never find myself judging others the same way. I have stumbled upon some pretty great stuff by people who, in reality, are not anywhere near the top of their field, but it doesn't matter, it remains great regardless.
I think the worst thing that can happen is that nobody finds what you have published. Marketing is difficult, even for hobby work.