I've done some emacs building on Windows before, and I think it's more to do with all the dependencies. There are so many of precompiled dependencies available

I've done some emacs building on Windows before, and I think it's more to do with all the dependencies. There are so many of precompiled dependencies available for 32-bit, but last time I checked, it's not the case for 64-bit, so you have to resort to compiling those dependencies as well. Though this situation may now be better, but that was major issues when I looked into 64-bit before.