I always understood the other emoji answers besides the „thumbs up“ to be about my reaction to the content of the post not a rating of the post.
So laughing: haha, that’s a funny story, you made me laugh. Not: Haha, you are so stupid that you post something so silly.
The whole spirit of the DISboards is that way. We aren’t mean to each other. So sad means: I am sorry, your story makes me sad. Not: this is a bad post that makes me sad that I spent time reading it.
As I said, the thumbs up (like) I think means both: thank you for posting this as it is helpful, informative, enjoyable etc. But it can also mean: this is a good post, I agree with this.