The GPL doesn't prevent you from linking to BSD software.
All it does is prevents you from redistributing the resulting binary under a license that could result in the user's freedom being restricted. I.e., the only thing that is prevented is (BSD, GPL) -> BSD, since the next step might be BSD -> Proprietary.
Right. I want to give others the freedom to use my software in propietary ways, so I put my software under a BSD license. This means I can't use GPL-licensed libraries.
All it does is prevents you from redistributing the resulting binary under a license that could result in the user's freedom being restricted. I.e., the only thing that is prevented is (BSD, GPL) -> BSD, since the next step might be BSD -> Proprietary.