"There is a definite right-libertarian bias on HN" https://news.ycombinator.com/item?id=21432833
"If you go against any kind of socially conservative or libertarian perspective it will get down voted and very likely flagged" https://news.ycombinator.com/item?id=20643695
"chilling effect on discourse from leftists" https://news.ycombinator.com/item?id=20804464
"a leftist can't have a sane discussion on this website" https://news.ycombinator.com/item?id=15926162
https://hn.algolia.com/?query=13110004&sort=byDate&prefix&pa...
I think it's ok to use the up and down arrows to express agreement. Obviously the uparrows aren't only for applauding politeness, so it seems reasonable that the downarrows aren't only for booing rudeness.
It only becomes abuse when people resort to karma bombing: downvoting a lot of comments by one user without reading them in order to subtract maximum karma. Fortunately we now have several levels of software to protect against that.
There is a great deal of difference between giving users the tools to express disagreement and giving them the tools to block out the opinions of those with which I disagree.
Finally, quoting Paul Graham isn't really an argument. Fine, it's his site, but I'm allowed to say I disagree with how the voting on his site is implemented.