"No snowflake feels responsible for the avalanche", as they say.

False analogy.

The average person in the west is not a part of these multi-national corporations.

This is like punishing the entire German population for what Hitler did.

It's not about punishment. It's about ethics and principle. If you receive X because you purchased it through a corporation, and learned that X was generated via exploitation, then it would behoove any ethical person to want to address the exploitation.

But not all westerners are aware that their chocolate was generated through exploitation. Also, assuming that they want to address the exploitation, what does it have to involve the migration of the third-worlders into the West? Why can't they address it some other way?

Yes, but those of ethical principles would want to address the exploitation once they become aware of it.

And I am saying that it doesn't have to involve mass emigration.

Indeed.

Not sure how you inferred offence from my post.

But when you say the West should make amends for it, it sounds like you are holding the entire west responsible for the actions of the multi-national corporations.

You were in a huff.