Probably, this issue has been one of the most controversial issues debated all across the Stack Exchange sites. There are pros and cons and they have their own reasonable and understandable arguments. My answer boils down to the following points:
SE is not intended for a discussion forum. Questions that can generate only opinion-based answers are always closed across SE. Its format doesn't encourage any discussion in an answer and comments. It encourages definitive answers and on-topic comments. Now, let's say a user asked "what is a good (the best) dictionary for learning a Korean?" such as What is a good digital Korean-English dictionary?.
There are two answers.
(1) Use Naver. (2) Dictionary app in Mac.
Wait a minute. Daum dictionary is better than Naver. No, there are not many Mac users. You can just use Naver or Daum dictionaries instead of using the dictionary app in Mac.
Are there any definitive answers in the above? They are all primarily opinion-based. How do you define good or best? What makes Naver dictionary better than Daum dictionary? That's your opinion.
SE doesn't encourage a question requesting for a list. The reason is an answer could be too long and too broad depending on a question asked.
SE doesn't encourage a general reference question. If I can find a resource for your question, you can find it on your own. You and I both use the internet. What else? Here is the list for Korean English dictionaries. Pick one and don't ask here.
SE doesn't encourage a question that helps only an asker and a few others (which is too localized). Is there anyone who doesn't have resources to study Korean? A question for resources is too localized.
I like the wordings of Chinese SE Help Center that read:
Can I ask for resources?
The short answer is: No, but it depends.
Subjective questions (lists, asking for opinions, polls), are
off-topic on the main SE sites, because they do not fit the Q&A format
We should draw a clear line between the two following questions:
Should not be allowed: What is a good (the best) website/dictionary/reference/Korean song to
Could be allowed: I have tried this and that (prior research). But I don't think this
resource has this explained (specific issue and point that needs clarifying). Can you recommend other
resources that has this better-explained (clear comparison between the resources)?
As previously mentioned in another post, there are not many resources helping Korean learners on the internet. If we can make one or a few canonical post which will be updated whenever there is a new resource found by a user, we don't need to worry so much about a question requesting for resources. That's what other SE language sites are doing. There is no harm in following other language sites on SE. They have the same platform and format.
Q&A is Hard, Let's Go Shopping! by the founder of SE
"Give a man a fish and you feed him for a day. Teach a man to fish and
you feed him for a lifetime. "Every question and answer ultimately
should be about teaching and learning -- yes, even the shopping ones.
(All emphases mine)