Two things: firstly, the analysis I've seen suggests that some kinds of business travels lose and some gain, depending on the travel patterns -- in particular,

Two things: firstly, the analysis I've seen suggests that some kinds of business travels lose and some gain, depending on the travel patterns -- in particular, frequent short-duration flyers (e.g., people who commute from DC to NYC twice a week) gain, while infrequent long-distance travelers (e.g., people racking up miles going NYC to Shanghai a few times a year) lose. So maybe the airlines think they'll one class of traveler for every one of another class that they lose? Secondly, the overarching assumption is that American (and its alliance) will follow the other major players and switch once the merger is done, at which point there won't really be anywhere to go, at least for people mostly traveling domestically in the US. They control the market.