I’m 100% on board with the idea that no one has any form of obligation to talk or otherwise interact with others. That said, if a person see someone attractive and wishes to see if the other person might be potentially interested in turn, what exactly is the polite and respectful way to go about it?
Obviously you don’t want the guy to start following you until that magical moment they remove your headphones.
If you don’t have a constructive reply, expect more men to look to the “wrong” sources to get one. You see, if your rule is to “never” do anything, expect only the respectful guys will do so. This leaves the non-respectful guys who will try and occasionally succeed, providing support for the “Jerks get the girls” narrative.