It is about freedom, just not the freedom of the programmer. It's about the users. Freedom is not an absolute condition, it's always a balance the rights of various stakeholders. The cliche is that my right to swing my fist ends where your nose begins. Most software licenses restrict the rights of the users in favour of the programmer. The BSD licenses are vary liberal but they only focus on programmers that want to use the code. As a user you don't know anything about your rights if code is based on BSD code. Usually its 'free', but there is no guarantee. The programmer has no obligation to the user. The GPL is about giving assurances to users. If software is based on GPL code the user knows for sure that he will be able to get the code and use it.