Indeed the name is confusing, and having a list of “Agree” from dozens of different people do not seem like a thoughtful use of electricity.
I can see a lot of negative “boosts” coming in, like “Meh”, “Duh”, “Boring”, “Pfff”, “Mmmm” and other stuff that really does not bring anything to the conversation. In a recent community I have set up, I started a topic explaining why the collection of reactions were chosen, inviting conversation, and explaining that no negative reaction was provided because we think that if you have some negative reaction to a post, you should take the time to explain the perceived issue, so that the community can actually solve it, rather than remain in a limbo.
I agree with @Lilly that this feature does not seem to bring anything useful to thoughtful conversation. I am starting to worry about the future of Discourse if precious developer time is spent on new features that would hinder conversation and pull the quality of discussion and thought downwards rather than helping the online discourse to enrich writers and readers. 
One might argue that it depends on the community, but really, it all comes down to how much raw materials and water we use for all this, and whether it is worth the move; is this for mass consumption and debilitating people, or is this to make the world a better place?