The same reason as to why you couldn't forbid military usage or commercial usage while still remaining Free Software. "The freedom to run the program as you wi

The same reason as to why you couldn't forbid military usage or commercial usage while still remaining Free Software. "The freedom to run the program as you wish, for any purpose" also applies to entities such as the EU. If you forbid it from using the software, you compromise this freedom, and thus aren't Free Software.