Firstly, we don't have to explain why we downvote... the reason is right there when you hover over the downvote arrow.
This question does not show any research effort; it is unclear or not useful.
We're not required to explain further nor should we.
There are many, many Meta posts across most Stack sites on this and the answer has always been NO.
If someone wants to leave a comment, they will but requiring a comment has never been accepted as a feature across any site that I am aware of.
Explaining why we vote usually leads to extended comments and arguments which are rarely useful.
If someone downvotes your questions, ask yourself...
Is this question the best it could be?
Did I thoroughly research for answers elsewhere or even to see if the question has been asked already?
Is it really clear what I am asking for?
Does this question really need to be asked?
The last one is important, does it really add to your enjoyment of the movie to ask why something happened or was done.
If it's not then the question probably isn't useful.
Take a downvote as an indication that something is wrong and review. If at the end of the review you still can't improve the question then you'll just have to take it in stride.
We don't always meet with universal approval...it happens, shrug it off and move on. It's just one vote.