YOU are the problem, you can whelie anything. Its just a question of experience and balance coupled with enough money to fix it WHEN you get it wrong. When that happens on a pushbike you just get up but it can have some nasty concequences on a motorbike.
Its all about balance point which is quite high, the same as the sweet spot when you whelie a mountain bike. Its high enough to sort of float, needs very little effort to keep it there. When you have hoisted it you need to cover the rear brake to stop you going over the top.
I can't do it, well at least not with any style and i've bust enough taillights to know when to give up.
OH BTW it WILL kracker your steering head bearings and your headlight assy will fall to bits, have fun.