I must admit that I have been quite surprised as to how unanimous the committee's opinion has been toward rejecting Montenegrin. At this point, though, with the ISO 639-3 code now fully approved, I think you are in error
in failing to acknowledge Montenegrin as "eligible". I may not have a vote here, but I am going to push back on this question.
The committee is basing its position on item #3 of the "Requisites for eligibility": "The language must be sufficiently unique that it could not coexist on a more general wiki. In most cases, this excludes regional dialects
and different written forms of the same language." The explanation goes on to give the reason: "The degree of difference required is considered on a case-by-case basis. The committee does not consider political
differences, since the Wikimedia Foundation's goal is to give every single person free, unbiased access to the sum of all human knowledge, rather than information from the viewpoint of individual political communities."
It seems to me that there are two reasons for this rule. One is to focus contributor efforts so as to encourage the creation of meaningful projects without a dilution of effort into lots of small, incomplete, less
useful, possibly conflicting projects. The second is to try to keep all meaningful projects operating on a politically neutral basis. But I've got news for you: on both grounds, the horse is already out of the barn.
In terms of effort, we already have four wikis running in this language: shwiki, srwiki, hrwiki, bswiki. The effort is already diluted, if you will. But one more is not going to change the dilution factor much—especially
given that many of the people who want to contribute to the Montenegrin project are not interested in touching the other projects anyway.
The reason for that is the second point: politics. The current projects already exist, and are already based in "individual political communities", whether you like that or not. So by rejecting Montenegrin, you are forcing
people into projects that already operate under the viewpoint of "individual political communities", and (sometimes) hostile ones at that. There is plenty of evidence offered at https://meta.wikimedia.org/wiki/Requests_for_new_languages/Wikipedia_Montenegrin_5
that the other wikis have not been fully open to Montenegrin political points of view. And even linguistically there is a tilt against Montenegrin. Serbian Wikipedia, for example,
is only about 5% Ijekavian, about 90% Ekavian, and the rest a hodgepodge. I don't know if the hostility to a more inclusive community was more in the past, or if it is more in the present, or both. But at
this point there is a history that many of the Montenegrin language advocates are not willing to touch.
"The committee does not consider political differences[.]" Good luck. It's political whichever way it goes. The only real way for the committee to stay apolitical is to follow ISO 639-3 down the line, at least where languages
are "individual" and "living". I don't necessarily think LangCom must do that, but understand that all such deviations from ISO 639-3 are political to some extent. Until now, LangCom could deny Montenegrin by falling
back on the SIL/Ethnologue position that Montenegrin was "another name for Serbo-Croatian". Still, starting now, it's a more political act to
reject Montenegrin than to accept it. Maybe the Montenegrin community's "win" at the ISO 639 committee was more political than linguistic. Still, that's the ISO committee's problem, not ours. At this point,
the formal world standard for languages recognizes Montenegrin as a separate language within the macrolanguage hbs/sh, and we should, too.
Finally, going back to effort: The test wiki, which I opened on December 12 (after the ISO -2 code was published, on the assumption that the ISO -3 code would be automatic), has over 40 contributors and over 350 main
space pages. It's the most active test in Incubator right now. We've got a group of people excited about this project and working hard to make it a reality. Why would we want to discourage that?
I think this committee well understands that only 20–50 or so of the existing Wikipedias really serve the core purpose of being encyclopedic resources widely available to a broad community of users. There are others "in between", but
most of the rest are small projects that mostly serve local language/culture communities. This project will be no worse that that, and better than many in that regard.
I wouldn't feel this way if there were still a single "Serbo-Croatian Wikipedia". But there's not. So at this point, it's time to move on, and to allow
the Montenegrin language community to build its project.