Walking for 30-60 minutes per day will give the same results.
Anything that keeps you motivated and entertained at the same time is accomplishing its purpose. Yes, walking will accomplish the same thing--no one is disputing this. In fact, brisk walking will accomplish the same fitness goals a personal trainer will, and is one of the healthiest exercises a person can do. I don't see the guy's point, other than wanting to bellyache?