even if Steemit/Busy/etc built up to a fraction of the big social media platforms' size, our investments here will blow the fuck up. A few hundred bucks of steem today could be thousands in a few years.

It's certainly possible. The wheels are in motion to get A LOT more people using Steemit. I'm part of a project to do just that, but I can't yet divulge what exactly that is. If we succeed, there'll be big things coming soon!