I agree with you completely on the fact that people don't understand the value of the comments. Yes, there are so many upvotes on comments. Of course, not on every single one but there are many Steemians who appreciate this kind of contribution and upvote comments with nice amounts.
I know that some people do it. But I couldn't do it. I respond to all comments just because I know that people spent time on writing them (and hopefully reading my posts), so I want to show that I do appreciate what they've done.
You are right. Going through curie posts is time consuming. I do love those posts though. They have a very nice selection. I enjoy engaging with people and I'm thankful for all these contests as they also motivate people to be more active on the platform :)