> Python has this: https://docs.python.org/2/library/ast.html so it is possible to manipulate code as data. It just happens that it's not homoiconic, but so what?

The difference is that when you can do it gracefully, you'll end up doing it and using this possibility to build your project. If you can't do it gracefully, you'll dread using it and will not consider it a possible solution to your problem unless all other options are exhausted.