I wrote a question (Is there any evidence that Filipino president Duterte's war on drugs is successful?) before and made the title "Philippines: President Duterte's war on drugs" and then @Carpetsmoker edited it with the caption "make title a question", to the title shown above. (Which I have no problem with as I respect @Carpetsmoker's editing decisions, but I didn't realise the title always has to be a question (or does it?)).
Is there anything to suggest the title should always be a question? to me the title is the subject matter and the question itself alongside the context of the question would be placed in the larger area of the question. or am I wrong in thinking this way, if so, why?