You are missing a Linux version. Yes, Linux has small market share yada yada yada, but you will find that a much larger percentage of new adapters and tech influencers are Linux users.
I was thinking the exact same thing, I feel very dissapointed every time I see something interesting at the top of HN, and when I'm going to try it out, there's no Linux version of it.
It's like you said, if they want a good number of beta testers/ early adopters, they should have a Linux version.