Excuse me. An opinion-based question: Which question is more opinion-based: liszt-s-566-schumann-widmung-v-s-liszt-liebestraum-no-3 or can-a-24-year-old-learn-to-play-violin-viola-proficiently? May I know whether the moderator's opinion based on this opinion-based label is well-reason sound or not?
Yes, I agree with the moderator's decision. The original question asking
what are the best versions of these two musics, such as in the youtube? I have watched several videos, such as Yundi Li, E Kissin, Lang Lang, Arthur Rubinstein
definitely was opinion based. Questions about what is "best" are generally frowned upon on StackExchange sites. See the help center for more detail. However, the edited version is much better and I have nominated it for re-opening.
Answering the question in your title, the definition of "opinion-based" is
answers to this question will tend to be almost entirely based on opinions, rather than on facts, references, or specific expertise.
I'm unsure why you linked the second question. It is not opinion-based and can be answered objectively.