@Akikako She didn't advice "a lot" of masturbation. She did advice that he should cut back just because he was doing it "a lot".
What you might be thinking about is that she also did advice that he shouldn't try to achieve "zero masturbation"?
But that makes sense to me. Just like in dieting, setting impossible goals for yourself will only make you feel bad and possibly give up. Step by step wins the race.
And while masturbating "a lot" can cause you mental and social problems, going into "sage mode" every now and then is only good for you. XD
(Moderation is the key, as it often is.)
(Also, about the "food" comparison, look up "bulimia". People addicted to food can indeed eat constantly, even without looking like obese Americans.)