Johnathan Thurston says the NRL has failed society by only handing an eight-match ban to Spencer Leniu, calling for a blanket 12-game suspension for all racial slurs.
Leniu was on Monday night rubbed out until early May, after the judiciary rejected his claim of ignorance around the connotations of the word "monkey".
In doing so, the panel completely upheld the NRL's push for an eight-week ban while also taking into account the Sydney Roosters prop's remorse and desire to apologise.
But as far as Thurston is concerned, the suspension is not long enough after Leniu told Brisbane five-eighth Ezra Mam to "f*** up you monkey" during an round one on-field exchange in Las Vegas.
"The NRL had a great opportunity to make a stand, not only for the game but for society as well," Thurston said on the Nine Network's Today Show on Tuesday
"I think the game has failed in this instance.
"I don't think the eight weeks is sufficient for what has been said and the mental scars that have been brought up with what our culture has endured since colonisation.
"It was a great opportunity to go 12 weeks as a blanket ban for all racial vilification if you are found guilty."
In a statement to the NRL's judiciary, Mam said he was "angry" and "disappointed" by the slur and immediately saw red upon hearing it.
One of the greatest Indigenous players in history, Thurston said he had been in contact with Mam and seen first-hand the damage of the slur.
An emotional Thurston also rejected Leniu's claims he did not know the meaning of the word.
"There's only one way that term is used, and that is racially," Thurston said.
"I understand he has owned up to what he said, but in the NRL we have the Indigenous All Stars match, Indigenous Round and an Indigenous strategy team.
"So we're saying and doing all the right things, but I definitely don't think the crime has fit the punishment."
NRL CEO Andrew Abdo said on Monday night that Leniu's eight-game ban had shown the game had a hard-line stance on racism.
"The penalty applied tonight underscores the zero-tolerance rugby league has for racism," Abdo said.
"From this sad event some important lessons can be learned.
"We will work with the players and the RLPA to continue to deliver important awareness and education programs and ensure rugby league continues to be the greatest game for all."