The article makes a coherent argument:

a) Anthropic believe that AI is an extinction level risk and that they are the only leading AI lab which takes safety seriously. In combination this puts them in the position of believing that they are the only ones who can save the world, which is reasonable to call a god complex.

b) Anthropic are engaging in actions which aquire and consolidate power in the form of control over powerful AI.

c) "The history of brilliant people convinced they know what humanity needs is a sordid one, precisely because they have convinced themselves that their intentions are good, justifying actions that very much are not."

I'm describing claims from the article and would not word them so strongly myself. But this explicitly does not assume evil intent.