Q "When someone tries to shame you with where you are from is it so wrong to strike fear in them with where they are going?"
If "where you are from" is something you cannot do anything about then this "shaming" is senseless, even unkind. It's not something you can benefit from, so it's best ignored.
If "where you are from" is to do with attitudes, thinking, ideas or something you can change then you could turn the "shaming" to your advantage. Use it as a prompt to review the attitudes, thinking, ideas or whatever is the target of the "shaming" You could thus better yourself and/or explain yourself.
If you strike fear in them with where they are going then you're doing them a favour by warning them. If they are wise they will take heed and take stock of where they are headed.