Rather, it said, the tribunal's mandate was "to protect the public through the provision of a safe learning environment for students and to maintain both professional standards and the public's confidence in the profession".
It said Barber had "a lengthy career" in teaching since 1994 but was now unemployed.
In April 2009 he was convicted and sentenced to nine months' supervision for behaving threateningly against his ex-wife and breaching a protection order.
Two months later he was convicted and discharged on two other charges of breaching the protection order, and in December 2009 he was given another nine months' supervision for three more breaches of the protection order.
In November 2010 he was sentenced to 200 hours of community work on each of two charges of breaching the same protection order and one charge of breaching the conditions of the supervision order.
He failed to report any of these convictions to what was then the Teachers' Council within seven days as required by law, but the council found out about them through police checks when Barber applied to renew his teacher registration in 2009 and 2013.
Both times it let him continue teaching, writing to him in 2013: "The breach of protection order was described by you as due to your love of your children, grief at the loss of your relationship with them and anger over the actions of your ex-wife."
But it added: "You cannot afford another breach of protection order. Such a conviction would be completely incompatible with ethical obligations."
Barber then began a new relationship, but when this relationship ended, his former partner's son served a trespass order on him in February 2016 barring him from visiting the ex-partner's address in Paraparaumu.
Despite this, he visited the address the next day. In July he was convicted of wilful trespass in the Porirua District Court and discharged without penalty.
Again, he did not report this to the Education Council, but the conviction was referred to the council by the Ministry of Justice.
He told the council in a September 2017 email that he had not actually committed a criminal offence, saying he suspected that his ex-partner did not give her son permission to serve the trespass notice on him.
"He describes the victim as dishonest, and contrasts her alleged lack of veracity with his own 'fine character'," the tribunal said.
Barber wrote in an email: "Both my previous partners have not told the truth. I cared for them both deeply. Unfortunately, they changed and in the end were dishonest towards and about me, largely due to their change of direction in life; people change."
The tribunal concluded that Barber "has no demonstrable insight into his behaviour and nor is he remorseful".
"We consider the cancellation of Mr Barber's registration to teach is the least restrictive outcome that can reasonably be imposed given his lack of responsibility for his actions."