I'm gonna preface this comment by writing that I don't know those two peoples and only checked the hated one channel and watched one of his video on apple. Feel free to correct me.

The key word is agenda.

To understand such behaviour it helps to identify those people motives. In my opinion, - maybe misguided - they are akin to any other influencers. They promote privacy and an associated 'hacker' lifestyle like one would promote vegan, fitness, makeup, etc.

The hated one shit on big tech but he also monetize his content, had a patreon and ask for donation. I don't see any peertube, mastodon or lemmy presence.

He does not provide those video out of goodness of his heart but has monetary incentives behind him, he has a brand, follower, etc. This is not necessarily a bad thing. However it need to be taken into account when trying to understand some decision, and a big one is why they focus on some stuff and not others.

From my limited expertise - I'm a human and I use the internet - fear mongering and drama are two important mechanism in the influencer tool-set. And using them help improve their brand so why wouldn't they?

Thanks for listening to my ted talk.

He said, that Signal server did not get a source code update since 2020. He was wrong. It did, this year February.

IIRC no, it was only updated recently. Git commits are shown chronologically according to their commit date, not their push date. So they could have committed back in February but only pushed recently.