Forgive me if im wrong, but didnt kankuro gnw's mystery use to cause ignition and poisoning?

why was he nerfed and now its only ignition, which makes less sense than poison?

Of all the characters in this game that are broken beyond belief, why was a never seen character the one that got nerfed?

Gaara kk has been broken so much that he is the worst character in the game now and thats just seen as normal, but kankuro who even years ago was not commonly used you decided that he is a character that is far too strong and needs to be weakened? What is the thought process behind that?