Yes a responsive version seems too much to ask in 2015 :) I use hn.premii.com to read the news on HN, it's using the API and it's... responsive.
Not true, there was one briefly but it was so hated that it was scuttled. People who use sites like this one tend to dislike change, in my experience.
That's not why. HN's design is very old and table based so it's not easy to make it responsive / mobile friendly. It's also not easy to change the design because the HTML is integrated into the code rather than being separate templates.
They're working on improving it but it's an ongoing process.
HN is actually pretty great on the Android default browser on an older Samsung phone. My only complaint is the vote button placement and size.
Other browsers like Firefox and Chrome completely fail at reflowing HN.