Hanging a personal US flag in the US is a symbol of national pride (often by veterans) or a gaudy "'murica, fuck yeah!" statement (something like a dual axle pickup you only drive to Walmart) depending on your leanings.

The specific claim was weirdly nationalistic, which seems reasonable since lots of users outside America use the “American English” keyboard layout, to the point where it’s not clear why that’s the right signifier. Probably more Indian users use that layout than Americans.

Nothing is wrong with nationalism, especially the Penn Jillette brand of nationalism you seem to be advocating for. I'm just not flag-obsessed and find it weird to have a flag in my periphery for ten hours a day.

Do I support my "local community" when I type on a given keyboard layout ? And when I switch the layout because I need to type in a different script, do I betray my "local community" ? And what about I live in a country that's not my "original" local community and need to use yet another layout ? Do I feel insecure when I don't see a flag I know in my menu bar ?