When you do that, the locomotives lose diesel and I gain diesel. When I copy a comment nothing is lost (except an insignificant amount of HN's performance, which I'm working with Dan to make sure to stay in bounds of).

It's open source. The point of open source is that you have a lit candle and I have an unlit one. Lighting mine with yours doesn't extinguish your flame; there are now two flames.

The site will eventually offer an extended API that shows content that the official API doesn't, like downvotes and [flagged] status. It's partly why I made it, since there was no way to see flagged comments without visiting HN directly.