Would you rather take the chance as Garner and many, many others did, resisting the arrest by the police and ending up hurt or dead? I'm sure some would say "yes" just so that they can claim some crap about how badly the police are treating them even though they aren't being treated wrongly. Fight it in court, not with the police. That simple. And you are a whole lot less likely to end up dead fighting it in court than fighting it on the street, with the cop.
In fact, considering the conviction rate here in the US, you actually stand a much better chance in the court room, particularly in the areas where the most recently incidents have taken place, than fighting the cop on the street. Maybe if the NAACP lawyers would take up the incidents where the people didn't fight the police, but rather took their issues to court, they would see much more support for their side.