I think this is mostly right. I'm also on the record as saying that having to manage your own keys is a major hurdle for the average person: https://www.scmp.com/tech/tech-trends/article/3236382/decentralised-social-media-super-app-elon-musks-dreams-already-exists-growing-interest-china

My point was more that having the code accessible is not necessarily a problem. It may be unsightly, but I don't think it's too confusing for people to understand. Many Nostr apps are visually fine. People who do not understand or care about the technical stuff can ignore it. But best design practice is to have all the technical stuff hidden until or unless it is intentionally shown.

Regarding Obsidian, the user base might be more diverse than you think. I suspect you're right that technically proficient users make up at least a plurality. But it does have a big following among writers. I see a lot of Obsidian-related content from academics, journalists and fiction writers, especially those involved in world-building. Pastors, too, seem to love the program for some reason, as do D&D players. I don't know what the exact demographic make-up is (and neither does the Obsidian team, apparently), but it does seem to bring together all types.