This is in sharp contrast, because CentOS usually only pushes minor
upgrades to -extras, and as you mention, only a small amount of packages
that are properly tested.
Fedora pushes quite major changes continuously, and a large amount of
them. You cannot expect testers to keep up with the amount and impact of
changes. The result is that packages will be pushed to the stable
distribution with to little testing compared to their impact, making Fedora
practically a beta distribution.
The solution is, of course, to only allow for very minor changes in a stable
version (security and reliability fixes). But Red Hat would never allow such a
policy, since it would be at odds with Red Hat's goals for Fedora. Hence,
my comment that things will only change if Fedora becomes more