Not gonna lie, I only ever see this argument when it involves LGBT+ characters. Harry and Ginny kissing in Harry Potter or the many Disney princess movies that involve the heroine falling in love with the handsome and charming prince? Never a peep. As soon as the characters are gay however, it's "Oh, I dOn'T sUpPoRt AnY kInD oF sExUaLiTy iN cHiLdReN's EnTeRtAiNmEnT rEgArDlEsS oF pReFeReNcE!"
I know it's anecdotal, but I have legit never witnessed anyone complaining about the many hetero relationships depicted in children's entertainment until they get called out on their nonsense like right now, and it's wildly inconsistent. As soon as you bring it up however, they always backpedal and claim that it's all sexuality that they're opposed to. I wonder why that is?
Queer people existing isn't a political agenda. Quit being a snowflake.
It must be because they're secretly gay themselves and are terrified of the existence of queer people. No other explanation.