Twenty years ago, when I was training pre-solo, a BE-18 freighter was cleared into position and hold at my home airport, under heavy IFR conditions.
He sat there for 6 minutes without saying anything. And then an F-4 landed on him. They found his body halfway through the #2 engine. The F-4 crew lived to tell the tale.
Fast forward: I'm in Las Vegas, at night, middle of the SWA arrival swarm, aircraft lined up for 20 miles to land on the left side. They taxi us into position and hold on the right. We sit for 5 minutes. I (the flight engineer) point out to the front enders that if any one of those landing crews pick the wrong runway, we're quite dead. I couldn't even convince them to turn the strobes on until we were rolling.
The moral of the story: it's an o.k. maneuver, I guess, but sit out there for more than a minute and you better be making some noise on the radio, watching your TCAS and listening closely to the landing clearances given. That accident in LAX was a parallel runway situation also....