BoeingBoy's absolutely spot on there.
Taken to its logical conclusion, this doesn't bode well for UA, US, AA, DL, or even CO. Consolidation's main benefit, of the type demonstrated by a UA/US merger, is prolonging the agony.
Nice to see you back here. While I agree with you and
BoeingBoy, consolidation could help the remaining legacies (prolonging the agony, as you say) by combining the few remaining premium fare-paying passengers (high-yield pax) onto fewer planes. Instead of UA and AA flying more than two dozen overlapping narrowbody flights ORD-LAX each day, a merger of the two could allow the merged entity to fly a dozen larger planes, saving signficant money. Same on ORD-LGA, where some of the frequencies could be reduced, spilling the cheap-fare passengers to the always-present LCCs. These efficiencies won't make the survivor viable forever, but it would help in the short-term. Plus, in some congested east coast markets, the survivor could run fewer large RJs instead of more smaller RJs, or substitute 737s and cut large RJ frequencies (while maintaining the same effective frequencies).
About the replacement by LCCs of legacy capacity reductions, there's a frequent view, especially among airline employees, that the LCCs are only able to expand because of contraction by their legacy employers. There's a single-issue poster over at Flyertalk who laments the growth of B6 at BOS and has repeatedly blamed AA for "running from the competition." I'm not tarring
BoeingBoy with this brush, as I've never seen him make this claim. But of course as customers demand more low-cost seats and fewer high-cost seats, and as legacy execs realize that they must reduce the amount of flying they do at a loss, the capacity reductions by legacies will probably be replaced by the LCCs. GM and Ford sell fewer cars than they did several decades ago, and Toyota, Honda and Nissan sell millions more than in the past. Passengers have come to realize that a seat on WN isn't all that bad and that B6 and VX offer relatively nice coach products. People have forgotten/forgiven Airtran for their Valujet mistakes and that airline has grown substantially. No doubt other upstarts will emerge to attack legacies. Eventually, they'll even do it on the so-far lucrative overseas flights.