I don't understand (because I have never been in that position). And the TV show Silicon Valley also promoted this logic.

However he exited at $30 million. Is his sentiment born out of a sense of nostalgia?

Surely he is in a better position to create something than he was when he created Vine?

Vine is a cultural unicorn that no one expected. The founder will be able to make another $30 million, but he will never be able to create something as impactful as it again.

Was Vine really that impactful? I only ever encountered a handful of links to content on Vine, and when the videos would play at all, they were typically just 20-second-long clips of something mildly amusing at best, totally disgusting at worst.

As far as the social goes, I've literally never heard someone say "check out my Vine" or "look me up on Vine" the way I hear it about Facebook, Twitter, Instagram, etc. (and used to hear about MySpace, LiveJournal, etc.…).

I'm genuinely curious: was Vine something big and impactful that I somehow managed to sidestep? Or were my experiences with the service typical?

Vine was very impactful on the members of the Vine community. Yes, outside of Vine you didn’t see much links to it, but once you entered the community it felt very personal. Maybe exactly because it was its own little place mostly sealed off from the web. There were real, caring relationships between creators and viewers. People were generally very upbeat and encouraging. Creators showed intimate moments of their lives, often non-flattering, because you were allowed to be vulnerable. You were encouraged to experiment and to express yourself.

That created a bond between content creators and viewers, and between creators and creators. Some creators became friends and moved in together. I really liked the intimate, unglamorous moments that were shared. I think viewers could relate to the creators and felt more content about their own lives because they saw that all others had similar lives. Vine created happiness.

In contrast, on Instagram everyone tries to show off great locations, their perfectly decorated meal, their toned bodies, their perfect lives. It is more about showing off than creating a deep, personal connection.

You don't live in the social/cultural circles where Vine is important and compelling and novel.

You are also completely discounting shortform video. The format hasn't really existed before in this way and there's an explosion of creative experimentation happening within it. Snapchat, Instagram, and Vine are all helping fuel it.

I can't really speak to it's exact origins but Vine was a major player in launching short-form video comedy.