It took many veterans developing chloracne and cancer and many civilians giving birth to defective children for the population to start protesting the chemical weapon and the government finally phasing out its use.
... except Agent Orange doesn't cause cancer that quickly, and the government phased out its use in response to stateside scientific studies with animal experiments, not veteran outcry, which largely didn't begin until after the Vietnam War as a whole was over and the long-term effects of exposure to Agent Orange began to manifest in veterans.