My bad I don't think I answered the question.
It's because Americans are feedom focused and wearing a uniform is seen as against free choice.
The whole concept of wearing uniforms is looked down on in America anyone in the hood is not wearing the whole uniform from any McJob correctly.
When I go to any foreign country I always ask them is the hat optional or manditory
They never fully understand the question but especially in the hood wearing the hat is usually a bridge to far.
Also in the states people take off or cover their uniforms as soon as they leave work.
But not counting any of that they did try to introduce uniforms at my elementary school and it was rejected most of the parents didn't buy them and the kids didn't wear them and this was in elementary school.
The culture is totally against that.
Even in Private schools there's a dress code by rarely an actual uniform not even a school tie.
2 answer u
I went to schools
1 had a strict uniform
1 had non uniform
Can u guess which Mrs Obama Visited?