For a start this isn't true. Go back and watch any of the games in the WC so far, and Milne does get swing, it's just not as pronounced or exaggerated as Southee or Boult - and that's not surprising given that a) he's bowling with an older ball (and in the case of the NZ v Aus game a much older ball) and b) his role in the team is to focus on being accurate and fast.
But setting that aside, Milne's roll in the bowling attack is being seriously overlooked by those calling for his dismissal imo. He's not in the team primarily to rip through sides with the new ball - I get that given his Bond-esque action and speed people expect that of him, but that's just not what he's there for. Sure he'll bowl a 3 or 4 overs with the newish ball, but he's mainly there to come on and bowl in the final 20 overs when batting sides are looking to start playing more aggressive shots. His extra pace and bounce in those overs can and frequently has proven to be the difference between the ball disappearing into the crowd, and the ball shooting straight up in the air. However, in this World Cup, Southee, Boult and Vettori have been so awesome that Milne has never really been needed in this capacity. Against England, Australia, Scotland and Afghanistan, the hard yards had by and large been done by the 30 over mark. In the one game where Milne's late-innings bowling was kinda needed - against SRL - he came through very nicely, carving through Sri Lanka's middle-lower order like a hot knife through buttery icing.
Initially, the biggest concern for me about Milne was the pace he was bowling at in the first 3 games. But now he's back to bowling in the 145-153kph zone now, so that's that. I agree that the fact that Milne remains largely untested going into the QF's is kinda worrying, and I am fretting over whether he's the best bet in that scenario. But the fact that he hasn't had much work to do in the World Cup so far shouldn't be taken as a sign that he isn't playing well, or at least isn't capable of fulfilling the role he was selected for.
