The whales-dolphins-minnows analogy has taken hold of Steemit in a big way. It's a pretty good one too and has been expanded to other marine creatures like sharks and blue whales in free-to-play games.
You could say Steemit is a free-to-play game, but it's not really the same. It's not combative.
I feel I have a fun new analogy for Steemers - A cosmological one. A key concept here is one of gravity. We know how Steemit works, everyone rallies around posts the whales upvote. The Trending posts get bigger and bigger as everyone is attracted to them.
Whales are the stars. They shine the brightest, burn all the fuel, to power the entire community. The pass on all their energy to the entire solar system. Without them, there would be no Steemit.
Planets are like dolphins. They are key members of the community and compete to orbit the stars. Some dolphins are massive, proto-stars. With the right density, they will one day ignite nuclear fusion and become stars. (I have taken some creative liberty here!)
The rest of us - well, we are mostly cosmic objects. One of the billions of asteroids, comets or maybe even space debris. We are all desperately trying to form stable orbits around other, larger bodies. Over time, we collect more material, and grow in size. One day, some of us may become moons or dwarf planets. While others may crash and burn into planets and moons.
All pictures courtesy NASA.gov
So, Steemit is a Galaxy of many solar systems. Stars, planets, moons and smaller cosmic bodies - all of which critically need each other to maintain a stable existence. I hope we shine through the universe (internet) for a long time to come! :)