As I say in the next article in this series, in the one specifically on Christianity, I think Christianity was compromised from the start, in that it began with more heavy-handed syncretism between Judaism and paganism. So if your social movement is compromised from the beginning, as Paul took over from Jesus and from the more overtly Jewish Christians (who lost out, thanks to the Jewish-Roman wars), there's no authentic vision for later Christians to cling to. It's always been a matter of cherry picking in Christianity.
Christendom is just the secularization of Jesus's countercultural movement, but that secularization happened early on in the guise of concessions to paganism and to Roman imperialism.
See this article too: