The top executive at United Airlines threatened to shun Boeing after the carrier’s fleet of Max 9 aircraft was grounded in the wake of the near-disastrous Alaska Airlines door blowout.“I think the Max 9 grounding is probably the straw that broke the camel’s back for us,” United CEO Scott Kirby told CNBC’s “Squawk Box” on Tuesday morning.Kirby lamented the fact that he envisions a five-year delay — which he calls “best case” scenario — for the rollout of the 737 Max 10, the latest version of the plane that ...