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Actually it includes the freedom to make licensing as difficult as possible for those who want to use your code.

The GPL is incompatible with several FOSS licenses including itself (GPLv2 only and GPLv3 being the best example) and such legal issues only serve to drive away potential users of those licenses.

Personally, that's why I find the Mozilla Public License 2.0 to be the only copyleft license I can trust. It's much clearer than the GPL, it doesn't have restrictions on dynamic linking, it is copyleft to itself but it allows code to be shipped under a defined secondary license. By default these are the entire *GPL family from v2, but it can be expanded to include other copyleft licenses such as MPLv1 or the CDDL if the developer so wishes, as long as the parts under the MPLv2 are available separately from the project under that license.

This stops license incompatibilities, something that the FSF needs to work on with their licensing scheme.