That's not the key difference here. The key difference here is that the content author has control of the output. In the app in question, the app is scraping the content and the app developer is choosing how it's outputted. That's why the app is in violation.
I never said reddit was. The app in question isn't exclusively limited to content on reddit. Since anyone can post content from any website on Hacker News, there are several content sources and none of them are being displayed natively in this app.
