Stack Exchange is not a good format for “big list” questions
Stack Exchange works best with questions that solve a problem. The problem can be of various types but they usually fall under one or both or two broad categories “how do I do this?” or “why is it done this way?”.¹ This second class of “why” questions is also about solving a problem, the problem of understanding a concept.
Answers to such questions generally aim at solving the problem. The best answers aim at being definitive: each answer should stand on its own and would be valuable even in the absence of other answers. Not all problems have definitive solutions — not only for “why” questions, for which multiple points of view are often a good thing, but even for “how” questions, there can be more than one good way to skin a cat. Still, definitiveness is a goal to strive for.
“Big list” questions, where anybody could add their own answer, don't fit in the Stack Exchange model. The problem with these questions is that by definition, each answer is not particularly valuable, it's only the collection of all the answers that is valuable. Stack Exchange is not good at organizing such threads with one item per answer. In particular, voting ends up reflecting primarily who posted first, secondarily the popularity of the proposed item or of the author, and only slightly how well the answer addresses the question.
https://emacs.stackexchange.com/questions/13197/big-list-what-do-you-use-org-mode-for is an example of the bad kind of big-list question. If you give it time, it will either sink into oblivion with many good items missing, or it will end up having multiple redundant answers and totally useless voting.
What are all the ways of launching a shell from inside emacs and what are their various properties? is a different kind of question. It isn't one where everybody can add their own item and all items are equally valid (if not necessarily all equally useful). Rather, it calls for an answer that not only lists the possibilities but also compares them. It doesn't just call for “eshell”, “shell” and “term” but also when you would use each of them. There is currently a single answer, not a big list of answers.
Inasmuch as “big list” questions can work on Stack Exchange, they must be structured not as polls, with one item per answer, but as wikis, with a single answer that people are encouraged to edit to add an item in relevant places inside the existing structure.
[big-list] is not a good tag
“big-list” is a meta tag: it's a tag that doesn't characterize what a question is about, but the form of a question or of its expected answers. This isn't useful: it doesn't help when searching for questions, it isn't a tag that someone might subscribe to (nobody is an expert in “big list”) or a tag that someone might ignore because they don't care about the subject (if people ignore “big-list” because it's a repository for bad questions, these questions should go).
Either a question is unsuitable for Stack Exchange, in which case tagging it is irrelevant, or it is suitable, in which case it just needs to be tagged to indicate what the question is about.
If there are “reference” questions on a topic, that you want to highlight because they are of general interest to anyone with interest in that topic, link them from the topic's tag wiki.
In making the case for, one thing I would point out is that Area 51 asks for our "answer ratio" to be above 2.5, and it is currently (as of June 16, 2015) only 1.7. This suggests that however we go about it, we should find ways to create multiple answers to more questions. This goal will be more challenging to reach if every question is constrained to have one definitive "right answer".
You're working for the metrics instead of working for the goal. Artificially making up questions with lots of useless answers defeats the purpose since it doesn't improve the site. Don't pay much attention to the Area 51 metrics, they aren't all that relevant; this has been officially recognized and new metrics may be provided in 6–8 years.²
Emacs has a relatively low answer/question ratio, but it has a lot of pretty good answers that evaluate the pros and cons of different solutions. That's better than having solutions spread over multiple answers and no way to tell which is appropriate when. This kind of quality is impossible to measure objectively (the best you can do is average the subjective opinion of suitably-selected people), so you won't find it in metrics.
¹ A third category is “what” questions, as in “what is this thing”; these are best answered by reference works such as dictionaries, encyclopedia, reference manuals and so on, but Stack Exchange can serve as a fallback when not exists.
² The official time for something to change on Stack Exchange is 6–8 weeks but this one is taking far more time than it should.