Can't speak much to the SO comparison but I can talk to the standards as I understand them.
A good, on topic question will be specific about what is being asked, and whenever possible it should contain steps for Minimum Viable Reproduction. If the community cannot reproduce the issue, it is difficult to provide good answers.
A good answer will be rooted in fact and contain references to back up any claims. In general any linked reference should be quoted (and abridged to the relevant information if necessary). Sometimes if someone needs to build breadth of knowledge to understand the issue I will just provide a "Related Reading" section with a few helpful links, but the general rule is consistent.
Whether or not we will close a question as being Primarily Opinion Based is a bit of a crap shoot. Sometimes a question is rooted in opinion but the answer is too important to just close the question even if that close reason does exist. It sure helps to have a question where those opinions can be backed up by facts and experience.
Back to your question, if you are using "literally" in the ... literal sense, then I believe you have misinterpreted the help article you linked. The "Ask anything here!" bit refers to the linked Salesforce Success Community as "here". I'll quote it here again:
What topics can I ask about here?
Salesforce Stack Exchange is for Salesforce administrators, implementation experts, developers and anybody in-between working on, or with Salesforce products such as the Analytics Cloud or Marketing Cloud(ExactTarget).
The best questions are those that have specific answers; Salesforce StackExchange is not a general discussion forum. If you are looking for discussion, ideas or opinions, there are several alternative forums specifically focused on Salesforce:
If you take that first bullet in context, the help article basically states that even if questions are off topic here, they almost certainly will not be in that community.
