I have a feeling that is going to alienate mass populace users.

The main thing I want from that sort of social media is to see original content from people that I know. I don't want to see the best cat video; I want to see my friend's cat video.

There are already plenty products aimed at the mass populace, I would love to see again more communities built for the niches. Not just in terms of topics (subreddits et al), but functionality and interactions. Because honestly I came to the conclusion that communities only work if they stay relatively small and focused. I haven't used Are.na enough to say anything about their community specifically, but their approach resonates strongly with me.

Sounds like a key feature.

I think we've learned by now that mass adoption is the death signal for any platform since it will bring in the spammers, advertisers and other undesirables which ruin the experience.

The application part itself I quite like. Some of the color contrasts are way to low and style over substance (my first impression was, that it must have been designed by a Swiss Architect), but what I do like a lot is, just how little noise there is.