Why has this package ONE file in the directory /usr/libexec?
Same with gawk, etc. Will be ever RHL ever FHS-compliant?
Nope, not totally. By concensus, even though libexec is not explicitly
enumerated in FHS, /usr/libexec is used for those programs which are
not intended to be executed by the end users directly but which are
not strictly libraries. Red Hat and Debian are known to use this
directory, as well as probably other distributions.
Some directory structure issues will probably be addressed by the LSB
(such as the addition of libexec).