I don't know if that seems obvious. They were talking about twitter the social media platform... I can't think of a single thing twitter has got going for it outside of the size of the message, and the size of the message isn't a huge advantage considering often times users use image macros rather than text (which completely destroys the space efficiency) and you could easily just have, say, size limited facebook posts or something similar.

Honestly, I stand by my estimation that interplanetary communication will probably primarily be done over email.

I'm not defending the central point-- I agree with you that the primary means of interplanetary communication will be email.

It's just helpful to discussion if we don't assume others are expressing the stupidest possible iteration of the ideas they describe.

The problem with a centralized service like Twitter is that there is absolutely no guarantee that you will be able to access it through any particular means.

For example, my only means of accessing Twitter are either through the bloated Web UI, which is unusable on most of my devices, or through Nitter, which is read-only and sometimes doesn't work due to Twitter's API limitations.