I think they're very hard to draft too, because guys that are really physical in junior aren't necessarily all that highly skilled, they're just more physically mature. That size/strength edge goes away in the AHL and NHL.
Plus, it's not something that's taught to this new generation, not in America anyways. USA Hockey has changed the rules so much for youth all the way to u18 that it really discourages playing that style. You have to be 'making a play on the puck' when you hit a player, if your stick isn't on the ice and in the area of the puck it's an interference penalty. Any hit on a player without the puck, even if he just released it, is a penalty (because you can't make a play on the puck if he just released it). Any 'big' hit is called roughing, doesn't matter if it's shoulder to shoulder/chest, if you blow someone up it's a roughing. USA Hockey also doesn't allow kids to ice the puck on a penalty kill (which is crazy at u18 because they can ice it in high school) and they don't allow tag up off-sides because they think it prevents dump ins and forces regroups (but it really just encourages off-sides whistles and lengthens games). But I digress.