A question in the form
Are they not...
Is it not... Is he not... Is she not...
Are you not...
can actually be a kind of exclamation that means "They are certainly...It is certainly...You are certainly...He|she|it is certainly..."
Consider the difference in these two questions:
Is the bus not arriving on time today?
Isn't her new baby precious?
They would be asked with very different intonations in actual speech. The first question is asking if the bus is going to be late. The second sentence means "I think her new baby is so precious! Surely you agree!?"
So, in your original question
Are some ministers not destroying the futures of the students?
it actually means
(I think) some ministers are destroying the futures of the students. Surely you agree!?