Unique does not mean good. Even so, as uniquely unappealing to the ear as Nicki Minaj's voice is (even before it becomes incomprehensible as human speech after electronic overproduction), her actual music, taking everything into account besides just her voice, is anything but unique. Any one of her songs is indistinguishable from any of the tracks of her contrived 'rivals'.
Actually, I take back that last sentence. As musically terrible as Lil' Kim and Iggy Azalea are, nothing is a more perfect demonstration of the fact that 'unique' and 'good' are not synonymous as hit single Stupid Hoe.