[stephenr]

I used to think this too.

/. had this back in the day (I guess still does?). Lobste.rs has this too.

The problem is people just substitute "downvote without a reason" with "downvote as 'trolling'" for any opinion they disagree with.

[zodiakzz]

StackOverflow solved this by charging karma for each downvote you make.

[stephenr]

Charging "internet points" doesn't really solve the problem. I am apparently in the top 2% of SO, largely based on four answers provided a decade ago.

[pedalpete]

I'd figure this is pretty easy to get around if you are potentially being downvoted for not providing good feedback as to why you are downvoting.