<< Why doesn't object code count as free speach, while sorce code does. >>
The source code argument is a thin edge of the wedge argument.
Once you get the Supreme Court to declare source code to be Free Speech, you can then easily make the argument that so-called object code is source code written in a difficult programming language called machine language. You get a couple of crazy skilled elite programmers on the stand, they read off and interpret machine language, and boom, object code gets the same protection that source code has.
The reason lawyers are concentrating solely on source code right now is because this is a more intuitive argument, more likely to appeal to ignorant judges.