It’s a real phenomenon I’ve only observed online, luckily not in person as usually people who travel here care about learning about the world. It’s not a top 10 tourist spot.

Online examples I’ve seen plenty of:

• Assuming someone is from the same jurisdiction, especially in legal matters, or asking “which state are you in”?
• Going into a non-US national instance and making one-sentence replies about Democrats and Republicans on irrelevant political matters (most countries like their self-identified republicans)
• Going into a non-US national site and assuming a company name is an American company with a similar name (reasonable, but still an example). For example, we have an NBC, and it’s very different.

I think the “Speak English!” example isn’t defaultism as much as it’s chauvinism. Defaultism seems more like telling them to leave if they don’t speak English.

I see many problems with it echoing those of mainstream mass media. Especially with the advent of billionaire-owned social media and the increasing viability of automated posting, we see the same inequality present itself - the richest can pay for bigger microphones and astroturf the place. Even just places like Lemmy and connected tools show what a world of difference it makes to be a little further away from the mass bot armies and the profit motive.

I do believe there are some types of social media which can be constructive, but these are not like the general-audience mass social media we see (facebook/insta/tiktok/youtube/reddit) or even the more direct derivatives, like most of the well-known Lemmy instances. But one must have an idea of why the social media is being made and design it around that purpose. Lemmy is ultimately a reddit alternative. And its most popular communities were/are either bunkers for banned communities or clones of subreddits, hosted on very general instances. There’s no defining vision. It’s an improvement, yes!, but it’s far from what a digital social space can be.