It's a real issue. Many people have found that clothing is often the biggest impediment to being treated seriously on the job.
It affects women and minorities in different but equally profound ways. Meanwhile white males can wear whatever and nobody cares. Bath robe to work? "He's a 10x coder, we just let him do his own thing..."
This isn't about a "dress code", this is about perception. You could have a company mandated uniform where everyone wears exactly the same thing and they'd still find reason to be suspicious of people.
I use the clothing problem as an example because it's the biggest one. There are too many stories of people not being taken seriously because of what they wear when what they're wearing isn't the least bit unprofessional or inappropriate. It's just how people project things onto appearances.
> Blind interviewing does not handicap anyone.
Can you name one company that uses an actual blind interview for a technical positions successfully? How about a company that can apply the same rigour to technical and performance reviews?