Many times when calling on a prospective client, I am asked to comment on someone else's work—work done by a previous agency or some random ad. Before I comment I ask for the brief.
When you provide a brief to five people for a communication piece, you will get five different approaches. The only way that you can comment on such a piece is if you know the brief.
If the job is done to brief, then that communication practitioner has done his/her job.
Of course, if the brief is wrong to start with then, that person should comment to the client just what he/she thinks is wrong.
Australian Tourism's "Where the bloody hell are you?" ads is a good case in point. If the brief was to cause a furore. it has succeeded. But, it has also offended quite a few people. Was this part of the brief? I wonder.