Whether easing off is more or less effective than cold turkey, and for whom, is a technical matter. GP is talking about something orthogonal: some people believe that breaking addiction requires suffering, so if you found a way to avoid it, you've somehow cheated, or hadn't really quit.

I'm not against people quitting cold turkey if that's what works for them, addiction is different for everyone and if that's the most effective way of quitting for a person then fair enough. What I'm against is non-smokers preaching that it's the only way as opposed to something like vaping when they're in no position to make such a claim.