Dependencies in RPM based distributions work in a different manner to the dpkg Requires/Recommends/Suggests method.
Generally dependencies in RPM based distributions can be considered as an equivalent to "this package will not work properly unless this dependency is met". However there is some artistic freedom for package maintainers to include extra dependencies as they see fit (either because they are not automatically detected, or because they feel that it is a hard requirement).
As an example, a web application in Debian/Ubuntu may have various suggests dependencies on MySQL Server packages. However, because the MySQL server is not required to be on the local web server, it is not a hard requirement, the same package under Fedora would have no dependency.
There is a problem with the RPM methodology, which is what you have identified, sometimes there are too many dependencies. A common question I've heard is "Why should this package include libraries for Bluetooth when I don't use Bluetooth?", items such as optional plugins that are included in the main application package, are generally the cause for this situation.