In your ideal world, how would someone even signal they are a "willing participant" without talking to someone?
It's supreme arrogance. Read the body language and just leave people alone.
If someone is up for talking they'll show the obvious signs - facing you, eye contact, smiling, that sort of waiting-for-something look/expression. I've had e-fucking-nough of people thinking they can "fix" me when I am trying to get some time to myself waiting for a train or whatever after a stressful day at work or being woken up endlessly by kids/neighbours/whatever.
Otherwise it should be "talk to anyone who is obviously open to and willing to have a conversation with you", at which point it's a total tautology anyway and you don't need a guide, it's just natural chat that you don't need to force on someone to make it happen.
I don't fathom what kind of trauma would lead you to take this positive, light-hearted advice to connect to fellow human beings, and to spin this into such a vile, evil, anti-social narrative.
How does that help?
Don't assume people want to talk. Respect boundaries, leave people alone.