TLDR: "Answer is a list" alone is a poor proxy for "the question is bad"; in some cases questions whose answers are lists may produce a new summary of information that did not exist before on the Internet and is unlikely to arise and/or be made widely available outside of a community like this one. Use "answer is a list" as a prompt for further thought, not to automatically generate a close vote.
Disclosure: I am the author of a recent list question, What LISP compilers and interpreters were available for 8-bit machines?, that did seem to be acceptable to the community; after 212 views (including at least two by diamond mods, apparently) it had attracted only one close vote. That voter asked here in meta "Are list questions OK again?", which I am answering here because that question seems to be a duplicate just to stimulate discusssion (though I'm not convinced that's a totally bad thing).
What's bad about "list" questions?
I am in general agreement with the StackExchange question criteria. I also agree that certain types of questions involving lists are not appropriate here, often because there are (or may be) better forums for them:
- Lists based on opinion that cannot be eventually reconciled to fact ("What was the best 8-bit BASIC?"). These almost invariably involve a too-broad or opinion-based question, so it's not clear that the problem here is really the request for a list, per se.
- Lists that are very large and don't rely much or at all on in-depth experience ("What were the games made for the Atari 2600?")?
- Possibly, lists that can easily come from a single or small number of easily-found sources ("What are the addressing modes of the 6809 CPU?") basically duplicate information already easily available. (But I could be swayed on this one.)
I don't think that the argument that one answer can't be chosen as the best holds water if the community is willing to make and support a community wiki answer, as happened with my question above; clearly that answer will end up being the best unless there's not even one person willing to integrate into it appropriate material from other answers.
The multiple-answer format is still useful in this "one community wiki answer" case, though, as demonstrated by the ZIL answer to the question above. It's not clear that ZIL is really a LISP (or wasn't at the time, I am now convinced it is) and whether or not it fit the spirit of the criteria for the question. Indeed, it prompted further criteria being added to the question and I am still consdering, because of that answer, how to further narrow the question.
Can "list" questions be acceptable?
"The answer is a list" is certainly a fairly easy criterion for categorizing a question, and everybody likes easy criteria because they can reduce the amount of thinking needing to be done. But I don't think it equates directly enough to "this is a bad question for Retrocomputing" that we can use it without further thought. (Many answers to similar questions in other exchanges, including the links posted in this question, say essentially the same thing.)
If we look at the one answer in the StackExchange meta (19 votes, accepted) every criterion for bad questions can be avoided by list-based questions; i.e., the problems it raises are all about something other than just the answer being a list:
- "[E]very answer is equally valid": not the case when using a community wiki answer.
- "answer is provided along with the question": not always the case with list questions. (Also, that example can't have a single answer.)
- "[T]here is no actual problem to be solved": particularly in Retrocomputing, going back and digging out information spread out over many historical documents and memories can be a real but also soluble (at least to some large degree) problem.
- "[W]e are being asked an open-ended, hypothetical question," "[I]t is a rant disguised as a question": clearly not the case for some kinds of lists.
I suggest that the criterion "the answer is a list" should not be used alone to decide whether the question warrants a close vote, but instead as a heuristic to prompt asking, "is this really a quality question, and what makes it so or not?" Look at the other criteria for bad questions (including those above), and some critiera for good questions:
- Is the question "finite and well scoped"? An imperfect proxy for this is, "is the resulting list likely to be relatively short?"
- Does it "have a constructive, fair, and impartial tone", "invite sharing experiences over opinions", can it be "be backed up with facts and references", and is it "more than just mindless social fun"?
- Does the question require knowledge likely to be distributed piecemeal across a broad community, as opposed to having authoratative sources (i.e., would the answer become one of the most authoratative sources for this information).
- Can the question be further developed to improve and/or narrow it, and is the poster doing so? (For this, comments on what's wrong with the question, beyond "answer is a list," or how to improve it would be appropriate.)