There were some benefits too (I started writing more substantial comments), but the net effect had some unintended problems, so I'm pretty happy they got rid of that metric.
Karma has some problems too, and could no doubt do with some adjustments, but I think that it's more useful to have it than not.
I'd rather highlight comments that are controversial: they have been voted on a large number of times, with nearly 50% up vote and 50% down vote.
Those comments at least usually represent an interesting diff from either what I already think or what is stock monoculture canon on HN.
Do you think it's useful btw to have bookmarklets on the mobile web? Until now, you were limited to safari extensions and intents which you had to install through the app store.
HN could probably do something similar and mitigate karma ranking.
I agree that it could use adjustments.
Real-life karma is a good thing, but karma points are mostly a bandaid for "no other way of trying to keep trolling and other poor quality communication down".
The serious downside of having karma is providing undeserved power and prestige via a high status and ability to have certain actions to those that don't necessarily deserve it.
But the only way to get rid of it and get similar benefit is to have a community that can elect users into power that deserve it, like StackOverflow's elections. It would be even better if you gave the power to everyone and they were all wise enough and dependable enough to wield that power as needed, but that is unlikely to happen anytime soon.
In the absence of karma you'd expect that would make a person happy: the story they liked is getting attention! But people get mad if they miss out on the karma of getting a story voted up.