Another person trying to make this a "Hacker News vs. Reddit" thing, which still doesn't appeal to the reason sectors of my brain. Definitely not a ripoff; Mashable's clearly grasping at straws again.
Yeah, if posting comments and replying to comments is a design rip-off, then every forum in the world is also a rip-off. Hacker News looks nothing like Reddit, and the internet can support more than one discussion site (obviously).
I'm always surprised when people get away with this. And especially when investors reward them with more cash