Society in the 60s: A white man kissing a black woman is heresy!
Star Trek in the 60s: Fuck you. A white dude is gonna kiss a black woman.
Society in the 90s: He... she... wherever was born a he or a she or whatever. She shouldn't be allowed to kiss another girl or whatever.
Star Trek in the 90s: The Captain acknowledges and accepts the woman for who she is while recognizing her as previously being a man. She doesn't get pissy about her past identities until the last season when she's in another host body.
Society now: Stay in your lane. Kirk kissing Uhura was just an exercise in white dominance which should be cancelled. Sisko was always a bigot for calling Jadzia "Old Man" because of his experience with the previous host even though Jadzia never took any offense.
Maybe modern society is taking offense even when art is pushing us forward.