Perhaps I should use myself as an example. I came here in 2008 because of the Strongest Start contest. Though I didn't win, it sure made a better writer out of me when I received those reviews. The 'regulars' on here have some great ideas and through the years have made very helpful suggestions since we are blind quite often when it comes to our own work.
Ray is correct when he says the old gray mare ain't what she used to be. My first year here was filled with one review after another, some flowery and full of BS, while others stuck the knife in. I think it's not so much that the membership is falling below normal, but that we as reviewers are also slacking off. It takes both to make this site work. I for one am guilty. I'm not reviewing as much due to life at my Animal Sanctuary getting in my way, but when someone posts and gets zero reviews, whether good or bad, it doesn't encourage them to stick around.
As for the "fly-by" reviews Ray mentioned, I for one have been guilty of starting an in-line, but only getting part of the way through it and realizing I'm rewriting the story, which I don't want to do. I always leave the door open and in my remarks tell the writer I don't want to rewrite their work and have given examples of what I feel they need to work on, but if they want more help from me, to reach out and I will be happy to help. And many have, both through private messaging and quickie notes. I don't do it just to grab points because, after being here for eleven years, I've got more points than I will ever use in a lifetime. If I point out to someone one time that they need to make sure quotation marks are both before and after their dialogue, I don't feel it necessary to highlight it every time in the remainder of the chapter. If I point out they are constantly changing tenses, then any writer who is serious about their work will go through the entire chapter and make necessary changes. I don't see the need to keep pointing it out. Therefore, your 5,000-word chapter with 25 paragraphs may only be highlighted by me in the first 10 paragraphs if you repeat your mistakes throughout.
MJ