Then why does Vimeo have a Windows Phone 8 and WinRT app while YouTube with a much higher revenue can't make one? Why does the zombie company Yahoo Mail bother

Then why does Vimeo have a Windows Phone 8 and WinRT app while YouTube with a much higher revenue can't make one? Why does the zombie company Yahoo Mail bother to a Windows Metro app while Gmail doesn't? Or perhaps Google doesn't want to support Windows Phone and WinRT for the fear of rivaling Android phones and tablets.