I have only collected information... food for thought...
Street photography is a type of documentary photography that features subjects in candid situations within public places such as streets, parks, beaches, malls, political conventions, and other settings. Street photography uses the techniques of straight photography in that it shows a pure vision of something, like holding up a mirror to society. Street photography often tends to be ironic and can be distanced from its subject matter, and often concentrates on a single human moment, caught at a decisive or poignant moment. Naomi Rosenblum
"Pure photography or straight photography refers to photography that attempts to depict a scene as realistically and objectively as permitted by the medium, renouncing the use of manipulation. The West Coast Photographic Movement is best known for the use of this style.
Founded in 1932, Group f/64 who championed purist photography, had this to say: