Or maybe it is just that the segment of the public that is expected to vote doesn't care.
I don't vote, and I care about this issue. Why don't I vote? Mostly because the things I care about are not made campaign issues. That might be common.
You don't have to vote on every issue, candidate, or seat – there's no penalty for skipping questions. I do this routinely for issues where I either (a) don't feel qualified/informed enough, or (b) only a single candidate is available (writing in "no confidence").
If you care, please vote – even if it's just for the one guy who pledges to hold the NSA accountable for its actions.
I don't vote, and I care about this issue. Why don't I vote? Mostly because the things I care about are not made campaign issues. That might be common.