I think context and audience matter a lot. The post seems to mostly be talking about acronyms in the context of writing that's aimed at a public audience, but a lot of acronym use is aimed at a much more targeted audience. For example, I work on a product that pulls data about plant species from various data sources. I'm not about to type "Global Registry of Introduced and Invasive Species" or "Global Biodiversity In…
The feeling of being an outsider because you don't know the acronym is just as real in non-public settings. The new guy on the team for example. There's a real feeling that you should already know it, even if it's the first time you've heard the other person say it. The first time you heard GBIF, did you know what it meant? How did you feel when you heard it?
At the time I didn't know what "Global Biodiversity Information Facility" referred to either, or why it was relevant to my team. Even without the acronym, I still would have had to go look it up or ask about it if someone used it with the expectation I was already familiar with it. I don't think the acronym had any significant effect on my experience of learning the concept.