Misha -
I balk at responding to your message given my uncertainty that this is the appropriate forum for such complaints, but:
"Reliable" refers to an object (in this case, a distribution such as Fedora) which may be consistently depended upon to work properly. It does not mean that the system requires infrequent upgrades to new releases. In fact, these upgrades are a part of the Fedora distribution's reliability; in order to support the constant advance of open source technology, Fedora moves rapidly. Its cutting-edge approach to the world of operating systems is clearly advertised, well-known, and part of its purpose. One can rely upon Fedora to serve as a dependable platform for the newest technologies in free and open source software designed to work with the Linux kernel.
While the lower maintenance overhead required for RHEL systems is a plus (and, indeed, one of its primary aims), this is achieved at the expense of support for newer technologies, many of which depend on software versions exceeding those available for, say, RHEL 6. Though RHEL 6 continues to be an easily maintained, secure, and stable platform, it cannot support all of the newer technologies available for Fedora.
You are comparing two operating systems with different purposes while holding them to the same standard of administrative ease in terms of maintenance. This is not a matter of reliability, but differences made necessary by distinctions in the distributions' purposes.
The Fedora project works very hard to minimize the skill and hassle required to keep the platform current. It is unfortunate that you are having difficulties, but it does not appear to me that you have been misled into them on the basis of the phrase you quote from the Fedora site. Typically, Fedora upgrades are smooth and relatively easy to perform. If you have specific difficulties, I might suggest you seek assistance on
ask.fedoraproject.org; there are lots of helpful people there (including myself!) who work to resolve such issues on a daily basis.