"crowd-sourced genealogy" certainly is not my point in being here - and most often what I see here by way of "crowd-sourcing" is more like "crowd-sourced fantasy/fiction" than genealogy. Too often, "crowd-sourced" trees appear to be just a matter of copying what someone found in another tree, with no thought or regard for (1) whether there is any record to substantiate what is reported, or (2) whether what is reported even makes sense on the most basic levels. It really does seem, in many trees, to be a case of "oooh, look, 'John Smith' is descended from Henry VIII, Charlemagne, Cleopatra and Noah, and my great great grandfather was named John Smith, so I'm also descended from those folks."
I don't think the point of any of the points made above is to keep others from benefiting by one's own research - but at the same time, I have to say that it's disheartening when someone merely takes what's there because it's public (especially personally created memoirs, etc.) yet refuses to respond to questions, or indicate why the materials are of interest to them. If anything, THAT type of behavior is what defeats the concept of "crowd-sourced genealogy," IMO.