Actually most Jewish and Christian scholars believe that the passage as a whole is authentic, although there may be some interpolations. For eaxmple, , "He was the Christ...". However, "For he was one who wrought surprising feats and was a teacher of such people as accept the truth gladly. He won over many Jews and many Greeks." is generally considered authentic. Even without the interpolations the passage corraborates important information about Jesus that he was the martyred leader of the church in Jerusalem and that he was a wise teacher who had established a wise and lasting following, despite the fact that he had been crucified under Pilate at the instigation of some of the Jewish leaders.
This seems to be a balanced appraisal.
What I find significant is that, knowing that most scholars consider parts of the text you quoted to be a later interpolation, you posted it 'as is' to bolster your argument. I'm constantly being lectured by Christians about how, without their belief system, morality would be impossible, and then they do things that in my field would immediately get them a reputation for shady dealing, if not actual fraud.