I have no idea. The area where Wales are weak is in the line-out - they lost two of their own line-outs today. If I'd been England coach, I'd have encourage to kick deep to touch, guessing that Wales would lose possession a few more times.
Did it though? Neither of the English scores came from a long kick. The try came from England putting pressure on a Welsh maul. Williams et al gathered every kick with ease
It's because it worked against Ireland and France. England didn't take into account that Wales had one of the best full backs in the world, someone who relishes high balls slung at it him. It was a strange, strange tactic.