Here's a better pitch based on your feedback and maybe more tailored to the Hacker News crowd. The Internet is broken as content primary pools behind walled gardens like Facebook and Twitter. These platforms are not open in the sense that the metadata is locked up inside them. Additionally, they're not very respective of the rights and privacy of their user base. Polar tries to reboot this by building out a generic d…
As for feedback, I'd strongly suggest focusing on UX above all else. I tried Polarized a while ago, and gave up on using it because it didn't 'feel' very usable. I know that's vague feedback, and I wish I could be more specific, but broadly speaking it just felt more like a great idea rather than a great tool.
The internet wasn't successful because of the idea(l)s behind it. It was successful because it was simple, practically and conceptually speaking, and anyone with a text editor could do something amazing with it ("look ma, the whole world can read what I wrote!").
Or another example: I get all warm and fuzzy when I think about Emacs and its extensibility and whatnot, but I use VSCode for most of my day to day coding because it gives me a nice default set of features that are well-integrated and presented in a unified UI. I also don't particularly like Apple and what it stands for, but here I am paying a premium for a MacBook (2015 model, but still) and OSX because if I'm gonna spend my day using a tool, it better feel right!