I have to agree with the sentiments others have stated. This isn’t a social platform, it’s a discussion board and everyone should be able to involve themselves. It would be too easy to just ignore anyone who disagrees with you, and people would use it for that. Even if your intent for said system is just weeding out the people who troll or only post contrarian things for the sake of reactions with little to no actual value.
I’m sure Blizzard would rather the discussions be more open for more rounded feedback, rather than just thread after thread of people agreeing with one another due to having everyone who doesn’t ignored.