People often speculate rather than answer. If you think you know the answer then you don't.
I think that downvoting and criticizing questions should be based on their (physics) content rather than on the particular phrasing - which may reflect one's individual habits, cultural background, or simply the turns of phrase used in the one's native language (many users of PSE are non-native English speakers).
On more scientific level: the notion that all questions have an answer, and that this answer is unique is simply not true. In physics we are closer to this notion, since we deal with the subject that can be extensively tested experimentally in controlled conditions (which is not always the case in biology, economics, social sciences, etc.) Yet, even physics theories cannot be proved, but only falsified by new evidence. In fact, thinking that our answer is correct rather than believing that it is correct is the difference between the science and a religion.
Criteria of correctness
There are also many known logical fallacies, where correctness of a statement is judged not by objective criteria, without perhaps even realizing it:
- Years of schooling make us consider as correct whatever the graders typically consider correct
- Popular opinion - e.g., judging the answer as correct, because it is highly upvoted
- Appeal to authority - e.g., judging the answer as correct, because it is made by a high-reputation user.
A popular anecdote is that the original idea behind the IQ testing was to give as many answers to the same question as possible, using different reasoning... but it became a multiple choice test, in order to adapt it to general population.