When people give me comments that say "Love it! Update soon!!!" I don't update for a while. I'd like to know what my readers think, not that they want updates. I mean yea, everyone likes updates, but everyone likes criticism too... well maybe not everyone, but I enjoy it. Anyway, I agree.
I give things to improve if I can find any, if I read it and think there's nothing to be improved, or can't think of any at that moment, I don't comment.
I try my best to give constructive criticism to the stories I read. I don't always do it, because thinking of a four hundred word comment after every chapter is kind of draining, but I try my best to write something useful to them.
Oh, yes, you're absolutely right... I think when I sometimes put 'comments are appreciated' people think they have to say they love it... if people don't want to subscribe, I want to know why. There was one very nice person who left a comment on my story saying "I liked it, but here are three things I would change." Two of the things I agreed with her on, one I did not. So I made the changes and I think my story is a little better now because of it.
I agree. I've gotten a total of maybe two or three comments out of all my stories combined that actually had criticism in it. And it was helpful. And I SO appreciate any comments I get on a story, but most of them do just say, "Loved it! Update soon!" and while it makes me glad to know people are reading it, it's not telling me things I should fix or keep doing.