simplified; diffuse and undiscovered damage/pathologies excluded as causes of aging without compelling evidence

This seems bad to me and unscientific sounds like a fair label for such practices. I don't know why you disagree.

Unscientifically claimed to be curable to some degree by specific therapies

Admittedly this usage is confusing. But judging from the arguments made elsewhere in the paper, they seem to be saying there's no good evidence suggesting these specific therapies will work. A lot of what he does seems to be highly speculative. Calling speculation unscientific seems fair to me, science is about going out and looking at the world, then creating ideas in response to what you observe.