I've always felt like a disagree button is kind of counter-intuitive to the point of a forum. Like, the reactions serve a purpose of giving feedback that would just be spammy in a forum context, like I liked India's post above because it made me laugh, it lets me express "lol" without just quoting the post and saying lol, which is a meaningless contribution to a thread. And same thing with like an agree button, you could expound upon someone's statement but generally, they said what you're thinking so it allows you to express your opinion without cluttering a thread with just an agree. Whereas if you disagree with someone, then naturally that's a basis for discussion due to differing opinions. There's a different take someone could express but they may just be content with hitting disagree and not engaging in a conversation. And if you hit disagree then add to the discussion anyway, that's just redundant. I get people might not want to engage in the specific conversation or the initial post might have enough substance to debate in the first place, so if you would've just typed "I disagree" with nothing afterwards it's good to have I guess.