ETA: Oops. Long ass post. Sorry. See why I am not on twitter? 140 character limit???
Re: judges lack of critiquing on Idol this year. (I'll connect it to Adam, promise.)
Yes, I think the lack of critique by judges is pathetic. What purpose do they have if not to act as performance and vocal experts pointing out the good, the bad, and the ugly? The audience wants to hear from "expert witnesses" who can identify problems that we cannot articulate. Experts who can inform our listening so that we can be better consumers/voters. (Not sure most of the judges have ever done that good a job of it, but at least they made some insightful comments occasionally, when not looking for sound bites.)
As for the effect of the lack of critique on the contestants, I am not convinced it would make a significant difference, particularly with James.
1) James did not appear open to suggestions or coaching. I don't know what all the vocal coaches, Iovine in particular, said to him, but I have to assume that the coaches have expertise to do the job. And from what we saw, James felt it best to go with his gut, with his opinion rather than theirs. It appeared that James does not have a great deal of discernment about his music and his abilities (or he wouldn't have tried some of the things he did musically and stage-wise).
2) James, as opposed to Adam, has probably had limited experience with taking coaching and direction. Adam had a plethora of experience with it from numerous auditions in theater, and from the daily notes directors give during rehearsal and performance. There are many times a developing artist or apprentice must just listen and make the suggested corrections, even when they do not agree or understand why. At that stage in their development they don't have enough experience to always understand why the coach's way is better.
3) If one gets good critique, if one is willing to pay it heed, one still must be able to do what is suggested. One has to have the technique to do it another way. The director says, "Brighten up the tone here" and the artist has to know how to manipulate his voice to do that. The coach says, "Take that phrase up the octave in your falsetto" and the artist has to know how to shift registers and support that style of singing. The director says, "Extend the phrase instead of chopping it up into three short segments," and the artist has to have the breath support to do that.
From what we saw when Adam mentored last season, his critiques were right on. However, most of the contestants COULD NOT do what he suggested. They didn't have the technique, experience or chops to do it.
That is another reason that Adam is considered such a dream for producers to work with. They say, "try it this way" and Adam can and does. The producers can craft exactly what they envision, because Adam can make it work. And, while, in the end, he may reject the suggestion for his own reasons, he is more than willing to give it a try first.
For all these reasons, I don't think the lack of judges' critiques has seriously affected the singers' performances or their lack of growth. But, a few constructive comments couldn't hurt. IMHO.