I don't like them. I think they are spammy and they make my contents comment section ugly.
My opinion is:
It let's me track if someone is misusing curation project that are under my management. We are building a better alternative like tipu but till then spamming comments looks like the option to track. (Your post has been curated by "curator name")
Example:
25 people can vote from an account then how to track who voted what? Who broke the set standards?
Also, we already have a solution to "click to reveal" for comment curations. Don't seem like high priority. Personally IU, Discovery-it etc comments are muted by me.