Before Software Update was integrated with the Mac App Store, Xcode was an optional install from the DVD that was also freely and anonymously updated via Software Update (beginning with Snow Leopard, I believe). It allowed me to freely and anonymously use my computer in a way that I wanted, so requiring an Apple Id makes it feel like that freedom was taken away. Everyone has a line somewhere, and that was the one I couldn't cross. Why do I need Apple's permission to install Mutt? It seems crazy and, yes, offensive to me.