People can do whatever they want with their work, including not sharing it at all.

But a great deal of the value that's come from open source generally has been that open source licenses haven't imposed the sort of usage-based restrictions (e.g. free for educational use only) that were fairly common in the PC world.

And, to your example, in the case of software the incremental copy that your friend sold cost you absolutely nothing. So it comes down to a purely emotional response to someone else making money off something you made.