Well after granting wishes for 10000 years you get bored and want to fuck with mortals. Plus some wishers are rude. I want this I want that give me give me. I bet a genuine wouldn’t fuck up a wish used for some one else. Like please cure all cancer or make covid 19 never have happen.
I wouldn't put it past the genie to screw with those wishes too. After millennia of people bitching that their seemingly selfless wish had unintended consequences, I'd wager broad reaching wishes would carry just as much screw potential as any other wish, rudely made, self serving, or otherwise.
Take that, asshole genie
you make a wish with the potential for most fuck up.