You're right. My assessment that GS and Mastodon are sides of an unmendable rift of worldview mostly comes from perusing source repo commit logs and comparing development speeds coupled with some personal biases I have toward anything with GNU in the name. I struggle with seeing it as anything but an "old school VS new school" type of thing and that's not entirely fair to you since I don't know you.

I agree on the privacy thing, though; if that wasn't clear. I've been very, very vocal with my new Mastodon instance admin on making sure they and their users are aware that privacy in Mastodon is at best a polite suggestion. It doesn't bother me because I just assume anything not encrypted is public. Other people don't understand that though, especially coming from Twitter where they've been trained to trust the company to keep their private data private (not that they make good on that trust...).

Steps being taken in Mastodon 1.5 are moving in the right direction by rebranding their privacy controls as something that sounds less like security and more like "Who gets to see this by default", but it's still a broken model and will remain that way until a fundamental protocol change happens.