I thought the writer was pretty impartial until he starts quoting these people that know nothing about tennis. I particularly thought it was pretty bad to quote people that have never watched or know anything, just saying that Tiger is better.
What they fail to mention is that golf is a skill that you can play without any athleticism, and tennis is a sport that requires movement and conditioning. You don't get to ride in a cart to each shot, and you use the same racket for a touch volley on top of the net as for a high ball to your backhand way behind the baseline.
Tiger doesn't actually play against anyone, he doesn't have to respond to their shots. The ball is right there for him to hit, and everyone takes their time and then they look to see who had a higher score. Roger is constantly playing against different strategies and different types of shots coming at him. In tennis you have to construct the point, and you face a huge number of possible angles, speeds, and heights for the ball, not to mention the different types of shots and the fact you are constantly having to move in any number of directions.
Golf is very much like darts or horseshoes. I've never seen a golfer out of breathe after playing golf.
Sorry, I was just going to post the article, but I couldn't help but post my opinion as well.