Which country are we talking about? Because that is not the case in the U.S. https://en.wikipedia.org/wiki/Personality_rights#United_Stat...
> They have used the likeness of Bruce Lee, Carrie Fischer, Prince, and Peter Cushing in commercial works, undoubtedly without prior consent.
Who is "they"? Who has been using Fischer's and Cushing's likenesses without contractual agreements?
> We also have "public" nude photos taken and distributed of celebrities on a regular basis (paparazzi)
Public photography has legal protections. Doesn't mean that if you took a photo of Obama at the gym you can use the photo in an ad campaign that suggests his approval of commercial usage.
They licensed their likenesses from their estate, or used licensed footage (i.e., film clips of Bruce Lee).
We also have "public" nude photos taken and distributed of celebrities on a regular basis (paparazzi).
Photos taken in public are not subject to the same tort concerns as private photos, or faked photos purporting to be of a celebrity.
You can't merely copyright your likeness.
As for socially, consider this: They have used the likeness of Bruce Lee, Carrie Fischer, Prince, and Peter Cushing in commercial works, undoubtedly without prior consent. We also have "public" nude photos taken and distributed of celebrities on a regular basis (paparazzi). This appears to be quite socially acceptable, so I'll run with the idea that "socially acceptable" is pretty fluid when it comes to celebrities likenesses.