Disclaimer: I am not holding or promoting the following.
But the meme is “if you’re gonna eat a sandwich, you’d like it better if someone hadn’t fucked it first”
I think the core of the meme revolves around possession. Seeing the “sandwich” as something to attain, and possess, and consume. Indeed, I would not like someone to fuck my lunch. But a person has an independent life where their value is certainly not graded in such a way. ( Or any way, in this context)
If you are obsessed with taking something pure, and only having your influence on it, for all time, then the virgin thing matters.