You're missing the social context here. First, this is never about using it's about dealing. Police enforcement efforts are almost entirely preoccupied with trafficking. Second, dealers are, by and large, bad people for other reasons. Your suburban pot dealer isn't the target of no-knock raids. The targets are guys with long rap sheets of felony convictions, often for violent crimes.
Drugs are a proxy in a war between police and gangs. Atlanta had 81 murders in 2013, versus 82 for London, which has 20x the population. To an extent the drug trade causes some of this violence, but it's just the tip of the iceberg. Atlanta is in a former slave-holding state and was segregated as recently as the 1970's. It's a city where 27% of residents, and 31% of children, are below the poverty line. Poverty is highly correlated with race: 33% of blacks and hispanics versus only 8% of whites. It's a city where 76% of poor families are led by women with no husband present.
Between the history of oppression and the massive racial disparity in the incidence of poverty, there is zero trust between the black majority and the white minority (which holds a majority of the economic and political power). This lack of trust is at the root of much of the conflict. Black and hispanic communities are unhappy with the crime, but also, arguably for good reasons, don't help the police shut down the gangs. At the same time, wealthier whites support the aggressive enforcement because they are scared and the negative side-effects don't happen in their neighborhoods.
This is not to justify no-knock raids for drug enforcement, but to help illuminate the mindset of the officers involved and how they justify their actions. I am in favor of deescalating the drug war, but that's just the first step in normalizing our cities, which see violence that is without comparison in the developed world.