i have just been speaking with an intellectual friend of mine (hes studying a PHD in medical research...) and he hears the phrase all the time.
in his experience it means a genius who for whatever reason doesn't want to do anything (whether through choice or difficulty in a given situation etc).
"willful ignorance due to lack of intellectual curiosity." doesn't sound like me at all.
people (fellow students, lecturers, teachers, former bosses etc) have said im very curious, open minded and eager to learn.