I'm not one to prejudge someone posting porn as one acting in bad faith. Its your prerogative to share porn, and nostr was designed to allow anyone to share anything they will. However to include nsfw on an unrelated hashtag is subversive.
The purpose of the grownostr hashtag is to attract people to the technology by giving them a rally point for content of general interest and to share things they're doing in life that other people might find interesting. It is hoped that grownostr would build a sense of community on a bitcoin centric platform for people that have interests broader than bitcoin alone. To include nsfw nudes under that category is dubious no matter how wholesome yours may be.
Most nostr clients aren't as fully featured as you suggest, and I you dont initially strike me as someone that intended to be rude. There are plenty of sex workers on nostr that know how to coexist with men that might have wives or children looking over their shoulder and its not silly or funny disrespect their boundaries. I'm only bringing it to your attention hoping you may have been mistaken about its purpose. You have to agree, there is certainly no shortage of porn on the internet and most prefer to not find it where they don't expect it.