Rebuilding xinetd-2.1.8.9pre14-6.src.rpm on RH6.1, resulting package can't be installed without --nodeps. Installation appears to work correctly. I can't identify a reason for the package requirements for specific initscript and filesystem versions. The initscript requirement is particularly troublesome as it imposes a requirement for a 2.4 kernel. If the specific versions of initscripts and filesystem are really needed, please add a comment in the spec file explaining why.
The reason for the required version of initscripts is the translation mechanism, the reason for the required version of filesystem is the dependance on /etc/xinetd.d. The reason for the filesystem was given in the changelog, while the initscripts goes under "gettextization" (which could have clearer).