No, you can't take a BSD-licensed program and make it non-free. What you can do is use it as rev 1.0 of a commercial closed-source project and dump resources into improving the closed fork and capturing share from the original code.
What GPL prevents that BSD doesn't is closed forks. Obviously some people don't care about closed forks --- some people may even like them on principle --- or nobody would BSD-license anything.
What GPL prevents that BSD doesn't is closed forks. Obviously some people don't care about closed forks --- some people may even like them on principle --- or nobody would BSD-license anything.