Slightly unrelated tangent but Discourse, the software powering the Obsidian forum, is open source underpinned by a commercial business model – they seem to be able to afford to pay their software engineering staff and stay competitive. I would also cite Metabase and Taiga (and hopefully Penpot soon) as similar commercial open source success stories so there are examples where it can work at the small to medium scale.
That said, ultimately I think the community should respect the wishes of the developers – I don’t think that hounding the Obsidian team in the forum is going to persuade them to change their minds and ironically engaging them in this discussion gives the team less time to work on bugs and feature enhancements. Ultimately they’ve made something incredibly useful and it boils down to personal choice whether you use their software and whether you financially support development.
p.s. anyone who is concerned about Obsidian phoning home should run it in a sandbox or use something like Little Snitch or Open Snitch.