You're right, and I think the sharing and community aspect gets a bit lost in the "no license" and "public domain" discussion. The liberty of one individual (or company) to take a project and lock it down conflicts with the freedom of others to gain access to both the code, and potentially other locked down property (e.g. documents, hardware).
As an author of GPL software, I not only grant users free access, I dictate that future changes and re-distributions of the software will continue to carry that free license. Some see that as violation of their liberty. However, in my opinion, the free licenses are about the software and community first, and developers of derivative works second.