Dont you think someone who is on nofap is more likely to have had unhealthy porno habits in the past?
Your post reads like saying "dont you think alcoholics anonymous would have the least amount of drinking problems of any population?"
I don't think it's the specific number so much as the feelings of shame associated with it that's unhealthy.
Why is the shame unhealthy? How could we even say, without knowing why an individual is ashamed? Maybe they should be. Some shame is appropriate (eg Trump ought to feel ashamed about many things, though he doesn’t seem to)
Nofap is targeted as an abstinence approach for porn addicts that feel they have a problem.