The following are two examples of questions which have, as of right now, registered a number—four in these cases—of close votes.
- How do you refer to a hyponym that is the same word as the hypernym?
- The purpose of “the” in “hammering a nail into the wall”
If you click on either question and analyse its close votes, you will find one of them judged to be "not constructive" and the other largely "not a real question", two inherently inscrutable and unhelpful reasons. However, none of the eight possible close-voters involved have bothered to leave a comment stating exactly what they find non-constructive or difficult to comprehend. I happen across at least two or three such questions every day.
When the fifth vote is registered on either question, I suspect that we will find that the close-voters are all experienced ELU users who are well aware that it's polite to leave at least one comment explaining why they believe that the question needs closing. I also suspect that a good number of said users normally do ensure that the questioner is provided with some form of specific feedback.
This leads me to surmise that the culprit responsible for this errant behaviour could be the SE "review" feature which, in many ways, promotes "lazy voting" as voters can go click-crazy in the current interface without taking the time to really analyse each question by visiting its dedicated page. It also doesn't help that SE rewards voters with badges.
So, is the "review" feature responsible for lazy close-voting? Does each stackexchange site have any knobs to control how this feature is used? Perhaps close voting could be tweaked so that it can only be done via each question's dedicated page.