yes, and per HN terms and conditions only YC and YC affiliated (as you quoted) can use the api legally. I don't license my content to anyone else and so it shouldn't be use by anyone else, even if it's available on a free-for-all API (nice move HN, btw).

that's the license for the API, not the content/data the API serves

>including without limitation the rights to use

'use'...arguably the sole purpose of the API is to fetch the data.

You are grasping at straws.