They actually say that it is - have you seen the famous comic where the three guys are watching the baseball game but the short guy can't see through the fence? They literally are saying the equity of outcome is the beginning and the end of their goals.
Edit: a long take on all the variations, by the meme's originator! https://medium.com/@CRA1G/the-evolution-of-an-accidental-mem...
The point is to demonstrate agency over the systems we create. What’s the flip side of that scenario? People aren’t given stools to stand on and tall people get to watch while short people don’t? Who built the fence? Why is it that height? Why aren’t there bleachers?
Is just sitting there doing nothing equality of opportunity somehow?
I think reading "head height" as the outcome, is a very short-sighted interpretation.
Like anything else, interpretation has nuance and you could read it both ways. On HN we're supposed to address "the strongest possible interpretation" in our comments, so I would try to apply that principle here as well...