Also, they use this slogan because being a mostly domestic carrier, they 'can get away with it', but also do cater to large numbers of a certain type of American, for whom the phrase might be catchy, and might make them jolt with silly patriotism upon boarding...
Bear in mind that for most people outside the US, Alaska Airlines is only an insignificant and obscure domestic carrier that most people won't ever get to see in their whole life.
You wouldn't possibly imagine ANY international carrier of ANY other nation paint something so utterly silly, rhetorical and nationalistic as that!
It would be not only socially un-acceptable, but would be considered politically incorrect. Again, in aviation I'd dare say that nothing -NO SINGLE PRODUCT- is 100% made in ONE country. At lest the raw materials are sourced elsewhere, and easily most of the manufacturing is made in foreign countries.
Can you imagine if BA, or Virgin, would write something along the lines of "proudly using Rolls-Royce engines"?? I mean, c'mon. Britain used to have slogans like these in the 1950s, like the one coined for cars "buy British, and be proud of it". Now it would not even pass the test of a local primary school board!
...Or Air France saying "proudly flying Toulouse-assembled Airbus jets" ???
Folks, you wouldn't even see a Russian airline in Putin's Russia writing "proudly flying Tupolev jets"!!!!
Really, Alaska's marketing phrase is out of time, out of touch with global realities, and reeks of old-school right-wing, rhetorical, paternalistic, nationalistic sentiments.
It's really time to move on for a part of America guys.... it's sad that people can't even wake up to it, and see how much wrong there is with this stupid phrase.
Can't believe how worked up you are over this. The slogan is there because Alaska airlines is based in, and has their main hub in, an airport (SEA) that is in an area where 'papa Boeing' puts the food on the table for a huge number of households. That is all. Get off your political high horse.