For what it's worth, I think it's impossible to retro-fit the existence of an anonymous individual at that distance of time, especially in the absence of any forensic archaeology.
I think that good christians are a force for good, as are good atheists, good pagans, and good anyones.
And as I understand the new testament (which is probably not much), it is the intention to be a good person that is paramount.
Having just returned from Jerusalem and seen close up the nonsense and cruelty inflicted by the believers of various cults, I'm even more convinced that if there was a real Joshua Ben Joseph with a message he would be bitterly disappointed at how it's all been worked on.