One of the (potentially) negative sides of the same phenomenon is the acceptance of and tendency towards memes. They can certainly be annoying, but a strong flow of memes is indicative of a lot of culture and ideas bashing up against each other until some of the bits stick together in a novel way.
A cleverly applied meme comment on a Reddit thread can easily get hundreds or thousands of upvotes. Front page HN threads don't even get any meme comments, because people here know that their comment would be buried immediately, if not outright deleted (I admit to being much less familiar with the inner workings of HN than Reddit). Reddit threads are definitely a place of quantity over quality, but the sheer volume of creativity swirling around is bound to uncover a couple gems.
All of that said, I've never viewed HN as a place for ideas to be generated. This is a fantastic whetstone with some brilliant minds, but it can also be merciless.
To put it in simpler terms, Reddit is more input-oriented, while HN is more output-oriented.
I disagree - I've had a few novel ideas here, they may not have been universally novel but were definitely ideas that came up from threads I read, that I'd not seen or considered previously.
Sure HN isn't structured towards this sort of creativity but it still provokes it on occasions.
Forums are as input or output orientated as one chooses IME.
Edit: this, https://news.ycombinator.com/item?id=8487385, might be an example - I've not seen config undo-history in browsers before?
If each account had a limited vote rate (perhaps tied to that user's activity), I think this might help to reduce this effect somewhat. Much the same analysis probably applies to downvotes: currently users will click the down arrow on anything they disagree with, rather than only downvoting comments that severely detract from the conversation. Of course you'd have to be careful about this system being gamed, but all voting systems can be gamed and it's not obvious that this approach is any more vulnerable than usual.
To some extent I think Hacker News' greater discussion quality is due to its poor user interface, as weird as that may seem. Upvoting/downvoting on a mobile device, for example, generally requires zooming in to hit a small target, whereas on reddit I don't need to do that on my iPad at all, and on my iPhone not as much. Commenting on Hacker News also requires visiting another URL, whereas on reddit it happens more effortlessly. These are small things but they can be the hurdle that causes someone not to bother to post that joke or upvote the 17th reply in a meme sequence.
I know this probably sounds like a technical solution to a social problem, and I don't mean to deny the important effect that cultural norms and community policing play. After all, subreddits have widely varying qualities of discussion depending on their community standards, and there's no question Hacker News' quality survives in large part due to community vigilance. But I do think the effortlessness of voting on reddit is a factor which contributes to the prevalence of lowest common denominator comments, and I'd be very interested in seeing reddit or other social forums experiment with imposing a scarcity of voting power.
What I think could be a better system is for everyone to be able to mark what they like and don't like, then have the option of sorting by votes of other people that typically vote the same way you do. So people that like a lot of meme humor will see that more, and those that don't won't. Add in the ability to select from various "clusters", so you can also have the experience of reading comments based on alternative tastes, then I think you would have something that is immune from being gamed.
HN comment threads are heavy on criticism, light on creation.
The fact that one can after reading an online article almost inevitably see all the problems they neglected to mention is less the readers fault and more the writers for presenting a biased opinion-piece under the guise of news. HN critics can of course be wrong just like everyone else but the majority of the time those comments are pointing out serious issues and providing the counterbalance.
As an example the indie games or games on mobile will always be more adventurous and maybe 1% true gems better than other markets because the market is so big and allows anything. Contrast to the old school console days where mobile didn't exist, filled with greatly cookie cutter clones and rarely an innovation because it was 'too risky'. The ideas were there, just no avenue because it was curated away.
I personally believe any open market will always beat a closed one even if 99% of the open market is not as good. The broad differentiation of games/apps for instance only happens when many, many compete. A closed/curated market too closely will lose out on some big innovations. The same goes for internet vs old school publishing.
Side note: reddit moderations and subreddit moderation provides participation and value but is also somewhat limiting in terms of creativity. Reddit has shifted from heavily voted/democracy to a bunch of smaller partial democracies with a few dictators (similar to workplaces) and does threaten that creativity a bit. However the ability to setup any subreddit and comment with any vanity account have added exponential value in terms of creativity.
Someone else mentioned that HN is a great display of creativity which is a good way of putting it. This (and places like Reddit, Digg, et al) are merely museums for the real art, which is being wrought out in the world.
If everything on reddit interested me or was of the same quality there would never be any experimentation (foolishness) and I'd get lost in my own little world.
A lot of people love the way the sausage tastes but they stick up their noses at how it's made.