It's perfectly acceptable for a human being to drive a a car, but driving one drunk is completely unacceptable. Conversely, there is no rule against creating or consuming art while intoxicated.
So to answer your question, because it is not a matter of life and death. Take your argument and apply it to mass produced goods that were once the realm of only skilled craftsman.
> Is a human sitting on a neighborhood bench in view of your house the same thing as a surveillance camera on a nearby telephone pole?
If a person never leaves and keeps notes, yes, it is exactly the same. I'd call the police for stalking. The issue here is privacy, which is tangential to AI reproducing the styles of known individuals.
> The AI software has only "learned" in the sense that it has operated on the input data such that it can now provide outputs that are of convincingly high quality to make it appear to "know" what it is doing.
Completely disagree with you about the nature of learning here. If a person produces art in the style of an individual, they have no idea the internal machinations of the original artist, they just "appear to 'know' what they are doing".