What's wrong with asking a question which may involve opinions?
For example, this question was put on hold. "A, B or C" or "A, B, or C" or "A or B or C"
If this site were about physics or mathematics, I could understand why such questions should be closed. However, this site is about the English language which is far from being an exact science.
Let's say there's a question asking whether a certain sentence is grammatical or not. Whether it is grammatical or not often depends on scholars' opinions.