A recent change in xmvn package was introduced that started to embed parts of it BuildRequires in the package built.
As this is a build tool and the maintainer refuses to listen to the concerns from others about this introducing needless number of rebuilds - if a problem is fixed in the required package, all packages requiring it needs to be rebuild. Note that this can go recursively.
With the embedding we can have different versions of the required package in various places so a change in the lowest level might need few rounds of rebuild to get the fix everywhere.
Also this introduces changes from upstream for every single package that ships pom.xml file and builds with it hence making communication harder with upstreams as we introduce these obvious changes.
I agree that this simplifies packaging but the cos of that are way bigger and introducing such change in secret without widely announcing it is breaking the community way of doing things. Also refusing to stay to the current state of affairs until the Java SIG agrees is not the right way to work with others.

Note that I'm bringing this to FPC as everything started from the proposed change to the Java guidelines and this change is introducing automatic deviation from upstreams for every single pom file we ship so FPC has to say its word before we even continue discuss whether such things can ever be approved so we don't waste our time in endless cycles.

Full log of the Java SIG discussion is here:
http://meetbot.fedoraproject.org/fedora-meeting/2013-02-19/java_sig.2013-02-19-16.00.log.html