the main reason for which is that certain customers can be alarmed by the sight of uniforms
I tend to find the only people who are alarmed by the presence of uniforms are in actual fact more alarmed by the authority they represent.
Must admit, I once knew a delighful young lass who signed up with the Met, and upon visting her at Hendon one weekend, arriving to the sight of her and her three room mates in smartly pressed police-totty uniform well, yeah it was kind of intimidating
They're not called the Filth for nothing.