To point out a positive is empowering. However, to be real, and truly honest with someone with whatever they are working on, to get better, either as an athlete, musician, anything a weakness must be brought to attention and thats where being critical may be valid. Balance is the key, but always start with the positive to have something to build upon. But I find it much easier to point out a positive to answer your question, knowing what is good, also gives me a good depth of understanding what can be bad.