I've been using open source alternatives for different purposes for some time.
Obsidian would've been a great choice as open source note taking software. As it is now, it's just one sale, one exploit or one corporate rug pull away from being turned into something else.
Third party audits are meaningless. They were done for one specific version of the code at one point in time. There's literally nothing preventing a malicious version of the software from being shipped. The same goes for plausible deniability on security vulnerabilities in the context of plugins (even with these alleged prompts that the user has to skip on purpose).
They are not making excuses, they stated clearly why open sourcing it is tangential to this problem at best, and they're not the only user to call out the hijacking of the thread. They have been quite clear about why they keep it closed source, so I don't know why you're making it sound like they are lying to their users.
Your rant about audits has little to do with the article too. Telling everyone we're going to get rug pulled is exactly the kind of performative FUD that is meant to get a reaction more than anything.
Speaking for myself, I'm going to keep using it, because nothing has come close to the convenience and performance. Would love an open source alternative to prove me wrong, but I haven't seen it.
That's not good enough for open source zealots. That's when you end up being the headliner in an endless flood of blog posts and detailing comments telling everyone you're a 'proprietary evil man'. It's open source or nothing. And how dare you make money.