I'm sure this is to appease brands and we can say a lot about that.
But I want to focus on one big problem with dislikes and down votes. It applies to Youtube, Reddit, HN and probably everywhere you can dislike something: too often people use it simply because they disagree with the opinion expressed or simply dislike to creator or author.
This really diminishes the value of downvoting (IMHO) and I'm surprised someone hasn't tried to address it by figuring out who these opinion downvoters are and just shadow banning them, specifically you let them interact with the UI elements but it doesn't do anything. My theory is you'd get a much better result.
You also have people who review bomb things and I'm not sure how I feel about that. It's a way to express dissatisfaction with, say, company actions (eg ridiculous DRM) and that has value.
You also see things like on restaurant reviews "giving one star because even though the food was excellent and we had a reservation for 4 at 7pm on Friday night, we had to wait 45 minutes when we turned up at 8pm with a party of 11".
I am inclined to think that downvoting and dislikking actually has pretty limited value with the way people use it.