@I7guyIt all depends on the objectives of the admins for the forum.
On many forums, the "like" button is a way to mitigate a lot of literal "I agree" posts. When you agree, there's often little to add - you're presumably agreeing with what has already been stated. If you do want to add something, you post.
The reason we don't see a lot of literal "I disagree" posts is most people who disagree and would be willing to post "I disagree" want to express what they disagree about. If users agree with their "disagreement", then they can "like" the "disagreement". If the don't want to take the time to articulate what they disagree about, then their opinion of "disagreement" isn't worth sharing. "I disagree" does not increase user engagement - it actually tends to deter user engagement by discouraging discussion.
The general forums current arrangement encourages user engagement, which is what MacRumors is primarily after.
MacRumors News articles are generally the worst comments. It's a flood of regulars trying to be "first" and make a "witty" comment (sometimes they are, most often they are not) that will get 50 "Likes" (there are users here with a thousand received "likes" who never contribute anything meaningful, just some variation of "Apple sucks"). News article comments do not encourage actual discussions or critical thinking, but rather a virtual food-fight (and why it's frustrating that MacRumors has a zero-tolerance policy on allowing separate forum discussions on current "news" topics where people could have, you know, actual discussions).
My gripe about the buttons in the news articles, particularly "disagree" button is that it doesn't break it down by type. A comment with 50 reactions looks pretty much the same if it's 5 agrees and 45 disagrees, or 45 agrees and 5 agrees. Having to stop and click the reactions score to see what is what makes it all even more meaningless, because no one is going to regularly do that.
Here’s a good case of explaining a Like:
there is way too much posted above that a Like could possibly cover.
Maybe I agreed with EVERYTHING here, but likely I didn’t.
In fact the part I agreed with so much, that I hearted it, was this below:
The reason we don't see a lot of literal "I disagree" posts is most people who disagree and would be willing to post "I disagree" want to express what they disagree about. If users agree with their "disagreement", then they can "like" the "disagreement". If the don't want to take the time to articulate what they disagree about, then their opinion of "disagreement" isn't worth sharing. "I disagree" does not increase user engagement - it actually tends to deter user engagement by discouraging discussion.