Four Maori dames - led by Dame Tariana Turia - said they supported his entry to New Zealand because he could serve as a role model on domestic violence.
They were backed by former Women's Refuge chief executive Merepeka Raukawa-Tait, who said people needed to be given the chance to reform.
Ms Ritchie said the lyrics on his latest album ruled him out as an advocate because it showed his views towards women had not changed.
Women were referred to as "bitches" on at least 80 occasions, she said. "How is that informing young people of a positive direction?
"If men and women respect each other, they don't use that language. If this man is truly reformed in his respect for woman surely that would be reflected in his most recent lyrics."
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Ms Ritchie also took a swing at claims by Brown's new supporters that the lyrics were representative of how young people spoke.
"It's a huge over-generalisation to say that's how young people speak."
Brown has concerts planned for New Zealand and Australia towards the end of the year but has found his schedule under threat.
Politicians in Australia said he would likely be banned because of his conviction for assault on Rihanna.
Brown's cause had been further damaged by repeated violent incidents in the years since.
MP Judith Collins - who lost a relative in a spousal assault - sparked the debate here saying New Zealand had "enough wifebeaters".
Since then, an upswell of support has come for Brown from Maoridom and Maori organisations, such as the National Urban Maori Authority which runs domestic violence programmes.
Brown used social media yesterday to offer his thanks to New Zealand supporters.
"Nothing more amazing than strong women. Thank you to Dame Tariana Turia and everyone who showed their support in NZ."