Where does Obsidian claim they’re open source? Where have they ever done that? And no, having a GitHub icon does not magically announce to the world “we are open source”.
In fact, their license page makes it abundantly clear they are not open source:
> We own and reserve rights to our content, including text, images, and code in the app, which is protected by copyright and other laws.
I get this argument if a company or product claimed it was open source and it wasn’t, but it just doesn’t work if the product in question makes it quite clear they are not, or even leaves it ambiguous.
So if they at no point claim they’re open source… what, exactly, is your critique of them? That they built a product that is so good it could conceivably be open source but isn’t?
> And are you suggesting that people normally click the license page?
As my comment says, I am suggesting that they explicitly say they are not open source. It’s not like that’s featured front and center on literally any other product’s front page, so I’m not sure what exactly your expectations are here. Do you want them to have in 100pt font “WE ARE CLOSED SOURCE!!!” plastered across every page? Would that be enough?
In fact, their license page makes it abundantly clear they are not open source:
> We own and reserve rights to our content, including text, images, and code in the app, which is protected by copyright and other laws.
https://obsidian.md/license
I get this argument if a company or product claimed it was open source and it wasn’t, but it just doesn’t work if the product in question makes it quite clear they are not, or even leaves it ambiguous.