Thanks for the thoughtful post.
Christianity definitely didn't start at 0 AD. If wikipedia serves, started at about 300 AD when Constantine started recognizing the group. There was that a council of scholars (I believe known as The Councils of Nicaea) that decided on what should be put into the compilation we know as the bible then the erection of the first church in 380AD.
Hypathia, the respected but troublesome figure, was murdered around 415AD, 35 years later. The Dark ages starting about a hundred years later (according to Wikipedia), presumably when a more widespread campaign of stamping out a competing vision of the biblical god becomes economically and politically viable. Join us or die ultimatum.
I contend is that there where repeated efforts to suppress or destroy information. Consider Galileo as an obvious example, and he was only put under house arrest because of his nobility. Furthermore, If you consider the most common method to convey information to be in the form of a story, killing people who know and tell stories destroys information.
I will admit, putting aside your interesting contentions for the moment, I may have applied the word you quoted in this historic context irresponsibly, not because I feel it would misrepresent what actually happened, but irresponsibly because of knee jerk reaction conditioning people have to defend their faith from such a challenge. And that is where the actual point gets missed.
Lastly, perhaps we both agree that history is written by the those who are victorious. The conclusions about central authorities with enough clout or central authority in regions being conquered will never paint a negative light on history retold, the requirement of being a truthful historic entry being optional, what is not optional is that their history be aligned to dogma of their allies, other church based political allies for instance.
In our time of government secrets, no credible historian will deviate substantially from official press releases in their interpretation of major events like 9/11 or even the Iraq war even though no threat has actually been issued against the lives of journalists or their families. The tin foil hat crowd is just ignored and make up that "static" portion of the bandwidth. If the message is still too clear, then attack a producer or directors credibility with more static.
In 500 years time, conjectures supposing the official view, for example, Iraq was invaded for oil can become another interpretation of how our energy dependency influenced historians to such conclusions. The declension may been be a part of a further hereto unfolding push to discredit such views.
In many ways, this latest trend of destroying information that doesn't suit the state, or whatever authority behind the state, is old hat, the only thing new these days is that we live in a world with the internet. For the most part, killing someone's image is more effective in killing their message without the martyrdom problem.