These kinds of questions aren't actually "allowed" as such. But the Indicator-question is an outstanding special-case.
The FAQ should rule them out altogether, as it currently does:
You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.
The question about indicators is incredibly useful and on-topic. Even though it's the sort of question we would normally close, this one has proven to not lead to extended discussion, poll voting or anything like that.
I fundamentally disagree with the practice of having special cases, but there is no discussion about it at the moment, no argument to close it. So I guess I'll leave that for the future.
This is just my opinion. I'm not sure, really. As soon as this question loses it's outstanding relevance, it should probably be treated the same as questions like "what native games are available":
This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. See the FAQ for more information.
At the moment, the indicator question is on topic, and it's significance is not (yet) historical.
Or to answer the title of your question:
Lists are a subset of questions that don't have an answer as such.
A question doesn't have to say "list of" to be a list, and sometimes it's difficult to tell. For instance, "what native games are available" is clearly a list, because there are hundreds, but "Browsing the internet from the command line" isn't, because someone will likely post an answer naming all of the command line browsers. Or that's what we'd hope for. (:
The discussion was continued in the Ask Ubuntu chat, as a result of which two questions were posted: