Don't take it the wrong way, but the intention was to keep our link visible for a little bit of time.
Making a ready-to-manufacture hardware project takes significant more effort than just writing a blog post or recording a video.
Links posted in HN tend to disappear in a matter of minutes from the new and even if you hit the front page hardly anything remains visible for more than a day.
When we launched Solo, our Show HN was taken down because Show HN should be something people can interact with and crowdfunding was not acceptable. We learned it the hard way and this time around we respected the policy and didn't create a Show HN. (For comparison, I'm just looking at Show HN now and there are video projects, that I can't try nor interact with.)
If projects like Solo/Somu, open source, security, and implementing a real-world applications like FIDO2 don't qualify as interesting for a hacker community, I'm more that happy to respect that and not waste anyone's time posting. But if they do, like I think, they should have a way to be showcased properly.