My daughter's school has a dress code so we don't have to purchase uniforms. But they do have basic rules such as khaki or navy bottoms and collared shirts.
As a parent, I love it. It has eliminated morning chaos and arguments. I am no longer the bad guy for not letting her wear something I deem inappropriate for school.
It also eliminates her asking for certain clothes because so-and-so has a pair. I put all of her school clothes on red hangers (her school color) and she dresses herself in the mornings.
So, I do endorse dress codes . . but maybe not a system as strict as identical uniforms.