Surprisingly, Apple makes a product for people that want a Windows experience on Apple hardware, it's called Bootcamp. I am not trying to be witty: Things like Bootcamp, Parallels, VMWare, and so on exist so that people who want the Windows experience can have it without forcing companies like Skype to try to make their Windows applications pretend to be Mac applications.

I have Parallels. If you log into the Guest account on my machine and want to run Skype, I'd rather you use Skype for Windows and get exactly what you want than deal with something that is kinda-sorta Skype for Windows, but not enough to delight you as a user.