I think that the extreme shunners (those who shun their own flesh and blood, their grandkids, kids, parents, etc.) do it because of an inferiority complex.
I think they have some internal conflict such as
* a secret "sin"
* or know they could be pioneering but aren't
* reaching out but aren't
* living with many material goods, rather than getting rid of the material goods and "simplifying" and living with the "paradise in view"
etc. so they try to make it up to God by saying,
"See, Jehovah, I do love you. See how I am shunning so and so..."
Ever notice how it's the most arrogant ones who do the most extreme shunning? It's like they have a chip on their block or something to prove. Then they cry over and over to the "friends" about how much it hurts to have to shun their beloved family member. Then they get sympathy and kudos and people talking about them saying how "spiritual" they are. My sister has even gotten to do assembly talks on the platform.
When I faded and started trying to get her to doubt, she went over the edge, quit her job as a social worker (she has a bachelors in sociology), decided not to pursue her masters and ... you guessed it ... began to pioneer!
All of this simultaneously began with her EXTREME shunning of me. I mean not even going somewhere if she knew I would be there. Didn't invite me to her wedding ...
And I know she feels guilty constantly and is always feeling unworthy of being "in the truth". I still haven't figured out what her "secret sin" could be but I am absolutely sure that in her case this is it.