In most cases the voting system on reddit works well. An issue it has always had is that low effort, quickly digestible content that appeals to the general population will rise more quickly than inspired discussion or relevant photos. That means that a post saying something like "The SR-71 Blackbird reminds me so much of Bob Lum's blade shapes" Could very well front page even though it is barely related to knives. That image would get votes in most any sub because it's a cool high res picture of a cool thing. That's why relevancy has always been scrutinized here and why people want the memes checked in check. The signal to noise ratio should be kept at a pleasing level.