Regardless of it being popular, it only opens oneself up for being discriminated against.
Hiring person might have a bias against people with blonde/brown/black hair. Oh! they look like they are cocky and difficult. This person reminds me of my ex, there is no way I could be in the same office.....
This list of biases are endless. Sexism/Racism/Ableism/Ageism/etc are all given a free pass if you include a picture, but become various shades of obscure without it.