i think many people's affinity for these puzzles lies in their logical reasoning and conclusion.
whenever there is a problem there is always a method to solve it.
perhaps people find solace in these things (i certainly do) when something in their lives refuses to be resolved by a rational and reasonable approach. these hair-pulling-out enigmas, inevitably involve a woman.
consequently, i hereby propose that any su doku found to be unsolvable by rationale and reasoning, be hereby deemed "a female puzzle".