I feel like there has to be a good reason. Because scrolling through long threads to get to a different line of thought is not very friendly.
Ask HN: Why doesn't HN have comment collapse, like Reddit?
1–5 of 5 posts
Re: Ask HN: Why doesn't HN have comment collapse, like Reddit?
#2This request comes up regularly, the last time two weeks ago
https://news.ycombinator.com/item?id=11355038
Summary: most users agree, some wrote browser plugin, some are willing to pay for a solution. It's up to the admins to find time to implement the feature.
Re: Ask HN: Why doesn't HN have comment collapse, like Reddit?
#3It will devalue the comments you write. Why bother if it no one will see it.
Re: Ask HN: Why doesn't HN have comment collapse, like Reddit?
#4Oh man it pains me not having it! So many threads have a really long first comment chain about a tangent within the article or about a related project.
Re: Ask HN: Why doesn't HN have comment collapse, like Reddit?
#5Some third party clients already support comment collapse :)
I'm keeping a list of all HN clients here: https://pinboard.in/u:tedmiston/t:hacker-news/
You can bookmark it, filter by web vs. mobile vs. native, etc.
For comment collapse, I'd look at Premii's client in particular.