Jehovah's Witnesses and Shunning Reconciled with New Testament

Jehovah's Witnesses shun people who fall foul of scriptural law, >Jehovah’s Witness kids grow up knowing that if they ever mess up, their parents will leave them — and that’s scary (quote from person interviewed in link above) and looking at what I believe are scriptural reasons for shunning, they seem to be from the following - **Proverbs 4:15** >Shun it, do not take it;Turn away from it, and pass it by. (NWT) - **Job 2:3** >And Jehovah said to Satan: “Have you taken note of my servant Job? There is no one like him on the earth. He is an upright man of integrity, fearing God and shunning what is bad. He is still holding firmly to his integrity, even though you try to incite me against him to destroy him for no reason.” (NWT)

(Job said "It is unthinkable for me to declare you men righteous! Until I die, I will not renounce my integrity!" - Job 27:5 - NWT) but how can Jehovah's Witnesses reconcile shunning in the manner prescribed by the organisation with Matthew 7:1 >“Stop judging that you may not be judged; (NWT)
>Do not judge, or you too will be judge (NIV) Romans 12:17-19 >17 Return evil for evil to no one. Take into consideration what is fine from the viewpoint of all men.
18 If possible, as far as it depends on you, be peaceable with all men.
19 Do not avenge yourselves, beloved, but yield place to the wrath; for it is written: “‘Vengeance is mine; I will repay,’ says Jehovah.” (NWT) and >You must love your neighbor as yourself. - Matthew 22:39-40, Romans 13:9, Galatians 5:14 & James 2:8 Plus, should you not be trying to stear them back to the correct way?