My assumption at this point is that there is _no_ such purely technical
argument. Carlos and Jeff have implied that RedHat's team is under
constraints that would prohibit doing so, and have implied that these
are for "management" reasons rather than "technical" reasons. As I have
no connection to their team, I am free to speculate on what those might
be; one that IMO carries reasonable weight is that breaking the "you
need a glibc 2.18 or later package to provide symbols of 2.18 or later"
invariant will confuse any users or support teams that run into a
problem with a 2.18-versioned symbol and are using their 2.17 library.
It would, I think, be good for someone from RedHat to describe a bit
more what precisely what their constraints _are_ and what their
alternate option is if the patch isn't approved, even if they are not at
liberty to share the reasons for those constraints or in a position to
debate them.