Big difference between an individual defending his property/family with his own property vs funneling that defense through a corporate crowd-sourced surveillance system.
Citizen and all other private security firms operate under the same laws as any other individual or company. It’s not like these guys went out and started committing violent felonies...
I think the vigilantism implicitly endorsed by Citizen is entirely typical of the historical American attitude towards how one should defend their property. Moreover, it speaks to the breakdown of law and order in California that an app that organizes a modernized form of "frontier justus" can find enough traction to get off the ground.
For example, in my neighborhood a few people freaked out over a guy going through people's trash cans (trash cans are located in the alley, so not on anyone's property). This involved lots of internet sturm und drang, with people arguing whether or not it's legal to shoot someone going through your trash.