As you may have realized, he was not talking about masturbation, but rather porn-fantasy. In fact, on that page Gary suggested that masturbating while thinking of real potential partners in realistic non-porn situations might be helpful.
yes, im aware of the fact that masturbation alone is not necessarily the issue, provided you can stare at the wall or ceiling and just enjoy the feeling, (a rarity indeed I would say). The problem is the fact that it is very difficult for an addict to disconnect porn fantasy from masturbation, and even if you are fantasizing about real people, what does that entail? where does that cross the line from real to fantasy? The answer I would wager is it is very difficult to tell. For example:
You work with a woman, lets call her Becky, and you find her attractive. You are swearing off porn but are still going to masturbate so you decide to fantasize about having sex with her. In that fantasy Becky is doing all kinds of things you find stimulating, many of which mirror what you have watched in porn that you now feel are a part of your normal desire (many acts that i wont name in order to avoid triggering someone reading this to use). Just because your fantasy now has a recognizable face, that of Becky, does that make it less pornographic in nature? See my point?
As an addict going on 5 months clean for the first time in my adult life, I feel it would be beneficial if we stop giving caveat's that derail true recovery and just take a firm stance. Why don't we just tell people that to be on the safe side, avoid all masturbation including to real people because it may harm recovery? I myself fell into this caveat years ago and tried just masturbating thinking it was totally fine as long as I didn't use porn or substitutes. Utterly useless and ruined my recovery, as I still couldn't get very hard to a woman or even feel much attraction at all. I would also wager to say if you give an addict a caveat, he is going to take advantage of that. It's just how the addicted brain works.
I think we poo-poo unhealthy behaviors and thought patterns with this addiction because the addiction itself doesn't directly lead to death. If this were an alcohol addiction, we would never say to a recovering addict: sure you can go lay in bed and think about drinking, or go hang out with others you used to drink with, or go to places where people are drinking. Instead we would tell them to isolate, get new friends, or better yet join the military or go to a treatment facility on the other side of the country.
If you are an adult man depositing your seed into napkins by yourself in your bedroom, I might respectfully suggest finding something more productive or interesting things to do. I remember Gabe in his videos saying that he focused his time during recovery more productively, and improved himself professionally. Occupying his time with things like learning how to play the piano, reading books, getting his personal trainer certification etc. I suggest doing the same. There are so many interesting things in the world to learn that will fulfill you so much more than masturbation! Save all of your orgasms for your spouse, it will make intimacy better and healthier.