Some package maintainers release pre-compiled binaries proprietary for systems such as Microsoft Windows or MacOS. It’s entirely up to you whether to do that; we don’t ask you to do it, but we don’t object. Please do not let anyone make you feel you have an obligation to do this.
If you distribute them, please inform their users prominently that those non-free platforms trample their freedom. It is useful to refer them to http://www.gnu.org/philosophy/free-software-even-more-important.html. You can say, “This program respects your freedom, but Windows does not. To have freedom, you need to stop using Windows and other software that denies your freedom.”