No one is villifying the scale, but recent research suggests that what a patient reports and how a medical professional interprets that report are not necessarily the same thing. From Dr. John Markman's unpublished research:
I think this could also be a good example of testing for construct validity. The researcher asked if the pain was tolerable and found out that their numerical scale was NOT detecting intolerable. This is a psychometric issue.
One of the recommendations for better operationalization: Asking a patient how pain effects their ability to perform every day tasks. I don't think this is a new idea (as a patient, I've completed such scales for PT) but it shows a move away from a numeric scale. I think this could be a good example of ecological validity: Pain, being assessed, as it exists in day to day life.
I think that if you use this piece, it would also be worth while to point out the strengths of the Baker-Wong. It seems to be popular in a wide variety for developmental research. Kids do better with faces, it seems. Also, this scale could be useful in a medical emergency with someone who can't speak or can't speak the same language as their care team.