::Killing with a necromancer requires a lot more preps and skill than many other classes, and a lot of people give up early. So you're getting a selection effect because only the more skilled people stick around to get to spectre.

Sorry bud, you're shooting yourself in the foot with your own argument. If they give up early, they're likely not even making it to 47 and thus voiding anything you just said.

Cheers
Jhyrb.