I didn't intend for my comment to be mean. Generally, I think that sometimes the most useful advice one can give a founder (like myself) is "you should consider to pivot". Sure it's not fun to hear, but it can save you a couple of months. In this specific case, I think it'll help the founders to consider that the pain they're aiming to solve might already be answered, better, by existing simpler solutions. I don't think the best comment to leave is always "Amazing idea, wonderful execution!!!".

Why even give "advice"? Why not phrase it as:

"I get a lot of value from HN: it's fast, doesn't require an app, curating is done by real people and the comments add a lot. I'd be curious to learn what types of content your product surfaces that's different from HN?"