The comments I'm referring to are the generic phrases and in-depth one word analyses such as "that looks great!" "you're hot!" "awesome!" etc. I admit I've been guilty of this and of course it's nice to give and receive praise and positive feedback; there is nothing wrong with it. It's just that I keep seeing journals and sentiment by artists that the DA community is not only about sharing your work but helping and supporting other artists. I think that even if you're not that active with DA (like myself) a few constructive comments, especially to budding artists, can make an impact. I would have thought that constructive criticism would be filling every comment feed but it's simply not the case.
I admit, I don't think the caliber of my own stuff is all that great and I find it hard to dish out my feelings or advice whenever it's not absolutely glowing. I do try however to make it a habit to point out what it is about a piece I like, or find interesting, or what have you. If I only wanted to communicate that I simply liked it without having to elaborate I can just it and be done. I guess critique requests are there to fill that gap but those seem to be requests for in depth analysis, opinions, and people that use bigger words I'm not familiar with. Also, I feel there is the sentiment that if an artist has a critique request out the piece had better be worth the time and effort it takes to perform such a task.
So in general I feel comments on a deviation, for the sake of the artists, should be somewhere in between just an ego boost and gut-retching analysis. You don't need to be an expert to tell someone what it is about their work that drew you to it. What we take in and decide to share with the artist and other viewers can be motivational, inspiring, informative, and hopefully improve everyone's experience. Seeing some of the inflammatory and rude remarks as well as childish and unwarranted responses by some deviants can make it intimidating or confusing to comment constructively. There will always be jerks and cowards who hide behind the anonymity of the web but I figure as long as you are polite and honest that most of the time what you say will be well received and beneficial... at least to people that are actually worth the effort.