My point is, if AA withdraws from the West Coast, and if AS (AA's de facto low cost partner on the West Coast) does not fill the gaps, then West Coast business travelers who need a major network carrier will be left with no choice other than UA. In the long run, it's a battle for share of West Coast-based business travel. If AA withdraws from California, AA loses a large chunk of consistent West Coast business travel base to UA (this is business travel base that fills a lot of flights other than intra-West Coast flights).

Of course, there are limits to the losses that any company can or should bear in order to maintain market share. From my limited perspective, it seems that a withdrawal from California would shift the market momentum so strongly against AA that the long-term damage would surely exceed the short-term losses. I hope AA will find a middle road, that is, to reduce (if necessary) but not eliminate their presence in these markets.

By the way, there is no direct low-cost competition on SNA-SFO, and the only competition on SJC-SNA is WN... and if you look closely at WN's advertising, you'll note that SNA is almost always excluded from their sale fares.