So? I never said they did. Determining the update load for a typical install is not quite so straightforward. Never clean the yum cache, let the gigabytes accumulate, and check with 'du' I guess.
As an admin, however, I can say from experience that the Fedora patch load is *far* greater than that of any other distro I'm aware of, both in gigabytes, and in headaches when one of the many, many, many patches does something unexpected. (Churn yields burns.)
There are *lots* of reasons I migrated the Fedora servers to other distros, and extreme patch load is one of them.