Hotpatootie -- How many current students are going to end up working in the NHS? (Will there even be an NHS to work in in a few years time?)
How about people opting for dreadlocks or braiding or afro styles for their hair? How are organisations to police those styles without slighting traditional styles for people expressing a certain ethnic heritage? What about people of mixed ethnicity, or race if you want to call it that?
As for universities issuing rules about personal appearance -- I would hazard a guess that yours was in a minority of one.
Better for students to get all the eccentricity of appearance out of their system before they hit the workplace. American students seem to manage the transition from school to university and into the workplace just fine. There is no need to train children from age four that some workplaces and occupations will require uniform. Children see their parents heading out to work wearing suits, etc., and they understand this will be their lot some day, in places where school uniforms are not worn.
In my DCs' high school the teachers and admin staff are asked to wear 'professional attire' - which seems to me after a few years of observation to mean no jeans or shorts or yoga pants or other clothing that doesn't look 'smart' or 'smart bohemian'; suit and tie are not required, and tailored clothing is optional but what is asked is that their clothes are a step or two above what the students mostly wear. Hair colours are generally fairly natural for he teachers.
Things have changed quite a lot since the 80s in US schools. Students are not normally sent home for violations of dress code in US schools, as most schools have copped on that some students who are inclined to be truant could easily abuse that loophole. There is also heightened appreciation of discrimination in most schools, and a commitment to work hard to keep students with problems of all kinds engaged in school and making forward progress.
Schools therefore tend to gear discipline policies towards keeping students in the building and in an instructional setting. In most high schools I am familiar with a violation of dress code would have to be pretty egregious to warrant any intervention, but if there was a violation the consequence would be to wear a PE uniform over the clothing the student came to school in for the day, with home notified. Further infractions in increments of three would be treated with escalating degrees of intervention that would never include exclusion because it is clothing we are talking about here, not stabbing someone.
The reliance on the magical qualities of uniform is a really, really lazy and unimaginative approach to discipline and pedagogy.