Full disclosure, I don't own or shoot a Weatherby, but there's one angle to the Weatherby approach I haven't heard mentioned here at all, that would seem to be fair in bringing up: Speed just gets the bullet to the target a lot faster, and that does remove more of some problems from the equation, right?
Sometimes that buck just isn't going to stop to browse and give you the perfect broadside shot, or you may have a perfectly still buck or bull, and just one step occurring during your trigger squeeze before you recognize it happening is the difference between gut-shot, a miss, or a dead animal you don't need to track for days. 2600FPS vs 3400FPS is more than just numbers. Varmint hunters value speed for similar reasons - it's not lightweight bullets just to save the pelts.