> it would put too much distance between them and the public
It's not just one person's opinion, either. The British police is (supposed to, it's stretching further from it under the endless cuts) adhere to Peelian principles. https://en.wikipedia.org/wiki/Peelian_principles
> The Metropolitan Police officers were often referred to as 'Bobbies' after Sir Robert (Bobby) Peel
So _that's_ why! :D