The Concept of cursing in the Holy Quran

The Quran verses of cursing is of great importance because it explains the acceptance of Allah for paradise, the fire of hell, the dismissal from the mercy of Allah, while the kindness and Mercy of Allah has no limits; but still there are peoples and nations have been cursed by the All Mighty Allah. They have been cursed by Allah, not because they are wronged, but because they deserve the cure of Allah. The Muslims are not allowed to curse anything, unless with evidences of Quran and prophet speech; since Cursing others is one of the Big Sins, so a Muslim should not make any Cursing unless with clear evidences. If All Mighty Allah has Cursed a unbeliever person or a nation, then it doesn't mean that if another person makes the same sin will be deserved the same Cursing, as the reason and factors will differ from one case to another.