Originally Posted by
BackrowSaint
If you've got a competent kicker at Full Back, they'll generally take drop outs and kick offs.
It's so the defensive line can push forward with the Full Back then hanging back to slot in to their organising role. You've got a fully set defensive line from tackle 1.
If you have somebody else taking kicks you are taking that player out of the line, plus the Full Back who still has to hold to organise the line after tackle 1. It's not just about who can kick it the furthest, but laying the best defensive platform for the set as a whole.