I wouldn't have thought of this before reading Dagon's comment, but I agree that 'disable downvoting completely' seems like a solution with few or no drawbacks at this point. Certainly I think it would be a massive improvement over the status quo, at very small cost (even if the result is just hacked in, it should be pretty straightforward to hack in.)
I think some people don't see this as a big deal because they generally ignore karma, or they just instruct others to ignore karma, but some of us (perhaps from a history of reading reddit, who knows) have it ingrained enough that there's at least a real "trivial inconvenience" associated with ignoring that signal, and there are associated negative feelings towards the site which are growing over time at a System 1 level.
I log in this morning on a whim, and notice I have -15 karma. I dig around for a bit and find this:
http://lesswrong.com/lw/nsm/open_thread_jul_25_jul_31_2016/ddjm
To be clear, that's a block of four comments, each at -10, for no apparent obvious good reason other than eugine nier has a vendetta against Elo. I've apparently just been hit as splash damage, since I had the gall to try posting on an Elo comment thread.
I dig a little more, and I find this:
http://lesswrong.com/user/Elo/overview/
That's Elo's page, and I see a pile of discussion-grade posts that are all bulk downvoted below visibility, again for no apparent obvious good reason.
I find myself incredibly disincentivized to post or comment as a result of this. My feeble amount of karma has taken literally years to build up, and to see sizable fractions of it wiped out any time I step on a eugine nier landmine is bullshit. Sure, it's silly to value karma, but I value it anyway and if a year of incidental effort can be burned in two days because one guy wants to be an asshole to me, then I'm done here.
This has been going on for months. Years even.
I understand the staff of LW are pressed for time. I understand nobody understands how the code works. I understand that maintaining the site is hard. However, reality is that which does not go away when we close our eyes, and reality does not care: no matter how difficult the problems are, the fact remains that this sort of thing is abusive and it is actively driving people off the site.
If you value LW, fix this. Use the force harder, site owners.
On the other hand, if you want LW to turn into another Kuro5hin, then keep doing what you're doing.
Prediction: 50% odds this post will be downvoted below visibility within two days due to eugine, and will basically disappear without trace.
Prediction: if this isn't dealt with soon, 50% odds I'll stop visiting LW completely other than as an article archive by year end, because there's no goddamned point in trying to use the discussion system.