I was reading up on the difference between whoever and whomever today and came across a question with zero net vote, and no answers. I thought that the periodic automatic deletion process would delete such a question. But it was dated January, 2016. Why is it still there?
Minimally? Because it's not closed, and because it hasn't been a year yet.
The exact automatic deletion criteria are complex. See: Enable automatic deletion of old, unanswered, zero-score questions after a year?