Interesting outro. Interoperability is presumably one very big reason for this protocol.
As for why, all I can say is, download Lagrange, go to gemini://bleyble.com/cgi-bin/random, and see for yourself. It's one thing hearing about it and a completely different experience browsing the geminispace.
The different experience is largely thanks to different content, not different protocol. The protocol just serves a gatekeeping role to keep the community small enough.
I think that the specifics of the protocol don't actually matter all that much. What matters is that it's sufficiently unappealing to filter out most potential users; you genuinely have to feel strongly about the state of the web etc to spend a lot of time on Gemini.
That was a terrible experience. For a start that site has an expired certificate, as do many of the pages it suggested, and of the pages that worked it was mostly people that dipped a toe in a few years ago and never came back or other broken function.
As for why, all I can say is, download Lagrange, go to gemini://bleyble.com/cgi-bin/random, and see for yourself. It's one thing hearing about it and a completely different experience browsing the geminispace.