The more egalitarian principle would be to not assume. I won’t deny that. People from more minority locales have every right to be upset at being marginalized.
But at the same time, whenever I read passive aggressive comments on socials from residents of crown countries or from EAASL people around the world bitching about US defaultism as if people are doing it just to be ignorant dicks, I can only think to myself, “Uhh, hello? What do you think the demographics of this space were? What did you expect?”
Americans are hardly the majority of the world’s English speakers, but for all the reasons you listed, they tend to remain a massive plurality, if not an outright overwhelming majority, of any mainstream online English language platform. No, that’s not a license to perpetuate US defaultism. But like… read the room, people. Your good fight is far more uphill than you seem to think it is.
I recently had a rather baffling experience trying to preemptively avoid this by downloading the stupid app right away, only to discover I needed the website version anyway.
I was attempting to add my Known Traveler Number to an already booked trip with Southwest Airlines, booked by someone else. I was able to link the trip to my account right away in the app, no issue. And I could see the KTN field for my ticket sitting there, empty, greyed-out, and not interactible. I opened up the moble version of their website, completely unsurprised to find it was identical to the app, except for the detail that the KTN field there was functional. Put in the information, changes reflected in the app instantly, and I was in the TAS-pre line that afternoon.
Why did the two versions obviously built from the same codebase have two different sets of capabilities? Why was the website the more capable of the two this time? I have no clue. All I know is I never want to be a developer at a corporation where I’d have to be responsible for this flavor of trash.