People wanted a dislike button, got a series of redundant emoticons with very little space for actual disagreement. Which is actually good, because it won't transform Facebook into a mess of flames and negativity. Wait, maybe it's already too late for that...
Well, the purpose of Reactions isn't to "provide a dislike button" like a lot of people wanted. The purpose of reactions is to provide an alternative for people who don't want to click "Like" on stories of tragedy (e.g. someone's loved one dying, someone announcing they have cancer, or even something non-personal like a news article about a mass shooting) because it sounds inappropriate, like "ha ha, I'm enjoying you…
That's not the semantics of the Like button however. The Like button's semantics, as used by most people, are "I have read your post, don't have anything meaningful to add, and agree with you and/or express my post-appropriate social action but do not feel affected enough or close enough to you on the social graph to leave a comment."
The meaning of a Like is extremely contextual. And most people know this.
Granted, a lot of newbie users get confused.