Personally I would never want to share my data but I know every details about me, my social profiles is out there somewhere, honestly it is really creepy but this is how the technology is.
I have used github for few of many project during my BCS, it always helpful especially when I was developing website with ruby on rails. I'll be honest, I am not that good of a develop and struggled alot
The first step is to be aware of what data is out there. It can be cross-referenced to learn more about you. I know there's a lot about me out there, but I don't share all my personal details.
Developing is not for everyone. You could still help with projects in testing or documentation