Thinking like the "common man golfer", hitting fairways is at best a 50-50 proposition on our weekend outings. We get lots of practice hitting out of the rough, and yes it is harder to get on the green from the rough. Hell, it's hard enough to get close to the green from anywhere.
For a pro, they are looking to land in a particular spot so the ball gets close to the hole. If they can get in that 10-15 foot range they stand a good chance of one putting. From 10-15 feet we are more often looking at a 2 putt. Hell, I'll take 10-15 feet from the hole every time. I'm usually looking at 40 feet, or a chip to 15 feet then putting.
And their greens are far faster and harder to hold than anything we play on a public course. Accuracy for them is everything. Getting lucky, for us, is everything. So it's a no brainer that someone with great tee to fairway and greens hit in regulation stats would win a tournament. The US Open demands this more than anything else.