I haven't been very active on LinguisticsSE until recently, but it seems as if, judging from the meta discussions, that this SE is having trouble bringing in traffic, despite the fact that it is a very interesting topic. It seems like a lot more traffic could be brought in by allowing questions that encourage discussion. I use SO, SU, ELU, MathSE, CompSciSE, and LingSE for all questions specific to these topics, but for every other topic, I use Quora. Now, they have a much different setup than SE, namely one that allows any kind of question, including extremely subjective ones.
We've all heard the saying "Never talk about religion or politics" because it can always start an argument, but the funny thing is, on Quora, even a question like "What's the best religion?" doesn't cause problems. These sorts of online Q&A communities mostly have intelligent users that aren't going to be offended by others' views like that. On that particular question, every answer was a long, detailed explanation of their own religion and why the answerer's belief system worked for them.
A system that allows subjective questions would certainly be viable on a site like Linguistics StackExchange. Imagine is someone asked "What's the easiest language for a native English speaker to learn?" If this question stipulated that respondents must cite reasons why, I'm sure there would be 5 or 6 answers with detailed explanations as to why an English speaker's mind would be able to absorb a particular language easily.
The most important thing to note here is that this sort of question would bring in traffic. There are dozens of lists out there ranking other languages by "difficulty," but without any specific criteria in sight. Questions like that would surely drive more people to this site through the search engines.