“Crazyguy”: “I didn't see anywhere in that chapter a mention of shunning.”
Romans 1:28-32 (RNWT) says: “Just as they did not see fit to acknowledge God, God gave them over to a disapproved mental state, to do the things not fitting. And they were filled with all unrighteousness, wickedness, greed, and badness, being full of envy, murder, strife, deceit, and malice, being whisperers, backbiters, haters of God, insolent, haughty, boastful, schemers of what is harmful, disobedient to parents, without understanding, false to agreements, having no natural affection, and merciless. Although these know full well the righteous decree of God—that those practicing such things are deserving of death—they not only keep on doing them but also approve of those practicing them.”
Maybe that passage doesn’t mention shunning per se, but, as you can see, the Unchristian terms which I highlighted above are all embodied in the process of shunning. (Just like with the WT’s argument against smoking – it’s not mentioned specifically in the Scriptures, but the essence of defilement and harming one’s neighbour would technically preclude it from being acceptable. But, of course, even in that case, nowhere does the Bible recommend actually shunning someone for that.)