Not sure what you mean by this comment or what exactly it is a response to but it is a universal statement and the fact that there are plenty of Jewish atheists makes the meaning more opaque.
Gottfried's article falls to a syllogism: Neocons are Trotskyites. Any deviation from Trotskyism is subterfuge.
I understand you to conclude that Gottfried is saying a Trotskyite can not change his spots any more than a leopard can so therefore no Trotskyite can be a zebra, if one appears that way it is deception. Gottfried is not saying authentic conversion is impossible, what Gottfried is saying that true conversion never happened in the case of the neocons. As the old left progressed certain members did not like the trends and deserted the movement - not their original cause. Their new movement was not a conversion to a new set of beliefs - they did not become traditional conservatives - they wanted to remake the conservative movement in their image, and did. The main point is while they see complete socialism (communism) as untenable and though having modified their theories over the years they never gave up their origianl faith in central planning (they are the planners) and that the heart of their beliefs from the beginning to this day is revolution i.e. changing man and society from what they consider to be wanting to the perfection they envisioned. Having read their works and heard them speak I agree with the analyses.
As fopr neo-cons, they reject centralized planning, generally support the free market, and support an activist foreign policy. That is not Trotskyite.
The real joke is today we have the Trotskying Workers World Party leading the anti-war movement against neocons.