US Airways Saga Proves Mergers Only a Band-Aid

Other issues include a relatively low amount of hedging against increases in fuel-cost expenses, as well as increased spending to improve customer service.

Despite unresolved labor issues, few dispute the wisdom of the merger. "You can't fault management, but the market has been brutal on the stock," Derchin says, as the cards have stacked up against the carrier.

Says Nelson: "A merger premium was introduced, then eliminated. The market is pricing in elevated jet fuel prices. There is economic uncertainty and possibly a downturn in air travel. US Airways is primarily domestic and has a rising cost structure, including looming labor cost inflation.

"Throw all of these things in a hat," he continues. "Any one of them could be the reason the stock has not performed well."