stacked into a single roster spot makes it *more* difficult to leverage that talent when it's in the lineup, compared to leveraging it when it's in the rotation (or bullpen).
WAR is a funny thing. It takes into account a player's total contributions for the season (or however many games that player participates in) but that right there is part of how the Aircraft Carrier concept rears its head in the rotation but not so much in the lineup.
A SP who's worthy 6+ WAR is a True Ace. He's a guy that takes over 90% of the games he's in, where no matter who the opposing lineup is the odds are long that they'll pull it out against such a talent. In 30-40 games (historically speaking here) that Ace manages to contribute all of his WAR, compared to a Mike Trout or Barry Bonds who needs the entire season of 150+ to produce as much value.
So it becomes easy to see, just using the above distribution of contributions, that an Ace is an unstoppable, unavoidable force in a baseball game. When he's on the mound, he controls the game. Period. But when Bonds is in the batter's box, bases are loaded, and his team's down by two, there is a legitimate strain of thought that permits you to, essentially, remove him from the board by sacrificing a run. There's no such mechanism for 'avoiding' an Ace--he's in your face until he leaves the game.
And just looking at Bonds' own run through the NL in the early 2000's, it's clear to see from his IBB's that this is precisely what opposing teams did to him. They regularly sacrificed a baserunner, or sometimes even a run, just to take the bat out of his hands. They wouldn't be doing that if they didn't think it was a net gain for them to do so, right?
So, said all of that to say ;-)
I think an Aircraft Carrier in the rotation makes roster construction and game planning a whale of a lot easier on the manager, organization, and even the rest of the team. The lineup can scratch out a few runs rather than thinking they all have to hit grand slam homers to win the game; the bullpen can relax knowing it's unlikely they'll need to come in early to save the Ace, and the other pitchers in the rotation don't have to square off against the other team's Ace. The trickle-down effect seems to manifest everywhere, whereas with a Mike Trout or Barry Bonds it's (almost completely) in the other team's control as to whether or not he can kill them in a given at bat.
So a Mike Trout or Barry Bonds makes it HARDER to construct a winning roster, and deploy it, throughout the course of a season. It's nice having that killer piece, yeah, but if you don't have a COUPLE of sluggers to line up behind Trout or Bonds, they're easily controlled by opposing teams. And if you don't have guys getting on base in front of your sluggers, hard to score runs...see where I'm going?
Civics lineups, Stars & Scrubs pitching seems to be a pretty good way to go about roster construction, given the above thesis. The 2001 D-Backs rode the formula to a world championship, after all...