The reason Parr was ground breaking is he took the colour work of people like Stephen Shore and William Eggleston - whose work was reviled by critics for eschewing the dominant monochrome aesthetic of "serious" photography - and gave it an ironic twist. All of those people stepped on the establishment's toes in different ways, and in doing so advanced photography as a medium. You can like Martin Parr's colour work or hate it, but to lack an understanding of its place in the history of photography is pure ignorance.