Why do people say that the Church "caused" the Dark Ages?

as a Historical fanatic I understand your pain. the belief the dark ages were scientifically backwards and latter the church caused it all is during the renaissance the intellects of the day wanted to distance themselves as far as possible from the harsh realities of that day and the "crueler" place it was. that thought became bedded in our cultural understanding, much like the inquisition, we started blaming what ever was prominent in the time as the source of the pain and "dark", the Church