Maybe they did good work and felt proud of it and thought the hiring managers could look past the content of the product of the company and look at the real work needed to deliver that product.
Exactly. That is why such a entry in your resume works like a great filter.
If I had worked in NSFW and an application would get rejected because of that I would sincerely thank my former job for saving me a job in an environment I would not want to touch with a ten foot pole.
If people in (even small power) like HR drones abuse their position as to flag a resume because of such a former experience I doubt there is a company culture of honesty, openness, respect or value of the individual.
To me personally a great filter to have.
If one is desperately in need of a job. OK - remove it and try to jump ship once secured in the current place.
> If people in (even small power) like HR drones abuse their position
I call this the traffic warden principle: Power corrupts. Absolute power corrupts absolutely. A really tiny amount of power, in one specific area of your life, corrupts even more.
(Also, FWIW, it's "people in (even small) power", not "people in (even small power)".)
Seems like a way to shock the people actually putting real effort into vetting a candidates resume/credentials.
Maybe a warning that it’s nsfw would cause less extreme reactions.