Why does Microsoft look so good here? (Score 2, Insightful)

I don't fully understand why Microsoft comes off looking okay here. Why is it so easy to "patch Windows APIs" and override kernel operations? Why is this common practice? From the original SysInternals.com article: "Rootkits that hide files, directories and Registry keys can either execute in user mode by patching Windows APIs in each process that applications use to access those objects, or in kernel mode by intercepting the associated kernel-mode APIs. A common way to intercept kernel-mode application APIs is to patch the kernel's system service table"... Sony did it and didn't think it through - left some bugs, and generally made a lot of people angry and worried... but Microsoft is at the heart of the issue isn't it? Why is it so easy to patch these APIs? Isn't this all just a Microsoft security hole that allowed Sony to make another one?