Are you talking about Drew or "those guys", whoever they are?
Let's focus on Drew. I've not seen him mention HN, which by the way doesn't require running non-free software, and he literally runs a free software competitor to GitHub. I've not seen him be rude to people using GitHub. He certainly strongly criticizes them.
I assume he uses GitHub to communicate with projects hosted there. If he does, I don't think he could be blamed for meeting people where they are. He is not arguing about this, he is arguing against hosting non free software on proprietary infrastructure and strengthen it instead of helping strengthen the free software ecosystem. Which he doesn't do. He doesn't host his projects on GitHub.
He could boycott GitHub to make an even stronger point, but I believe that isn't practical at this time when you are part of the open source community. And running a whole GitHub competitor is way more than most people do for this cause. Accepting to reluctantly use GitHub (or Discord, or whatever) and spreading the word against its use is not contradictory.
Hypocrisy would be telling people not to use proprietary infrastructure to manage your free software project, and then hosting on GitHub.
Specifically about podcasts because that's what people seem to take issue with here: podcasts are usually hosted somewhere else, in addition to Spotify. Historically, podcasts are handled with RSS feeds, there's nothing more standard and open than this. It would be wrong to force people to use Spotify to hear his podcast, but that's not the case. He also should accept to be hosted on Spotify. When you are spreading ideas, you should want to reach people who are not yet as aware as you are in your cause. If you stay outside the world you criticize, you don't reach people inside it. And more importantly, he didn't mention Spotify at all; in particular, he didn't say "please host me on Spotify". Podcast ≠ Spotify.
I see hypocrisy nowhere.
Activism is hard, you know. You often need to do compromises for you activism to be efficient. Nobody is perfect. Should you wait to be perfect before making something for your cause?