[mattlondon]

I hate these sort of things. Like everyone is just sitting there hoping, hoping for someone to strike up a conversation with them. Oh thank god someone has started a conversation with me! /sarcasm

Respect people's boundaries please. Don't force yourself on people unless they're obviously willing participants.

People put extroversion/introversion as like this binary, permanent thing that cannot be changed. In reality I think it is a spectrum that changes throughout the day and the situation. Someone might be introverted at 8am on their commute, but a wild extrovert at 9pm in the bar. Don't assume, don't try to "help" people you know nothing about.

[granfalloon]

What's being "forced"? And what boundaries aren't being respected? If someone attempts to strike up a conversation and you're not interested, you can signal that. Or just be direct and say you don't feel like talking. Sure, that can be uncomfortable, but you can't expect humanity as a whole to repress its social nature just to spare you occasional, fleeting moments of mild discomfort. (And despite the wide spectrum of social inclinations -- I'm definitely on the introverted end -- I think it's accurate to say that humans, as a species, crave social interaction.)

In your ideal world, how would someone even signal they are a "willing participant" without talking to someone?

[mattlondon]

Because it is this "talk to anyone" thing, like if they say no you just need to keep trying because really deep down they just don't know how nice you're being by giving them a chance to talk to you.

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.