The purpose of downvoting is not to express disagreement. Disagreement requires words.
Downvoting was solely as a means to sort posts. You’d downvote non-constructive threads not worth reading, and upvote good ones. You still have this sorting feature—but instead of downvoting, you simply choose not to upvote (“like”) posts you don’t think are interesting.
Unfortunately, downvoting was not used constructively. People did in fact use it as an easy disagree button, which created a platform where only mainstream opinions were allowed.
And it’s incredibly easy to think that because an opinion is popular, it’s right. But you would be blown away by how many popular opinions that are completely wrong (this goes for everywhere in life as well). For example, imagine how many of your parents that thought video games were unhealthy and made you violent.
If you want a platform where you only see things you agree with and like, you can go to Facebook. Disagreement is what creates discussion, and challenges your opinion intellectually.
On a side note, the forum was designed by Blizzard’s web design team, and they already said that all the other Blizzard gaming forums would eventually be updated to use the same forum structure as the Overwatch forum. Downvotes simply don’t belong on a constructive discussion forum. (Even the good discussion forums on Reddit also implemented a “not a dislike” tooltip on their downvote button as they can’t actually remove the button.)