The problem with being a nerd (as all here are) is you tend to overlook your own nerdness and castigate nerds you see as further down the pecking scale. I grant you the information bar is much lower on reddit and roughly comparable to facebook but with the unchecked ability to flat out lie and invent without any official sanction. It is no place for the thin-skinned or those of a sensitive nature as minor disagreements can result in extremely personal attacks which is why most of the people who get banned from polite discourse end up there-no one else will entertain them.
I strongly dispute that being in a place where 1000s of people are daily seeking out 'tank-wreck' photos is an unproductive activity for those who are looking for specific tank-wreck photos. There are huge numbers of such photos being posted and though it is not unusual to find the same old favourites endlessly re-used now and then genuinely 'new' and historically significant pictures are discovered. I can tell you that (for example) running down leads provided from reddit I was able to discover a source for some PK photos no longer in the Official Archives and several 'new' photos that provide different angles on previous versions of 'history'. I see it as a version of 'Google search' with, in my case, enough nuggets to make it worth the effort to keep winnowing.