I believe that all of that kind of defeats the point of "gemification" of
the standard library.
If I remember correctly then this was not the only reason made in favour of
gemifying core. One, for example, was that it becomes easier to change
existing code, correct bugs etc... - this may help distributions such as,
say, debian, when there is some known bug already fixed, in a gem release,
and it can be quickly updated, without having to wait for e. g. x-mas
release or pull out some patch manually. So that was one additional reason
for gemification.
I think there are more reasons for gemification.
Anyway, I believe your proposal/question is mostly related to Hiroshi, so
we should probably wait until he has time to comment. :)
There is something I seem to be missing, or perhaps not fully understanding
yet, and that is: what will actually be changed as a consequence of this?
You mention potential benefits but not any (possible) drawbacks of the
proposed change (if there are drawbacks). For example, Greg mentioned
"We also need to consider working locally.", so perhaps this affects the
workflow of other people.