Just to be clear: you are asking how a negative, critical, "this is stupid" article made it to the top of Hacker News?
I think this is a good sign for the Coin creators. IIRC Dropbox and AirBnB had similar negative buzz when they were announced. The YCombinator forum seems to like to bash implementation of ideas, specially by throwing other ideas which in theory are better (ideas are dime a dozen anyways).
They also bashed Color.
Hah. Fair point.
I upvoted both the Coin link and the link against Coin. I find it's an interesting discussion either way.