Because it's Big Brother.
You're not wrong about cell phones, BUT there are ways a person can reduce a phone's intrusions/spying. Flock cameras give no such options. They're watching everything you do, where you go, etc.
One problem is the claim is that they do not track people, but they clearly do based on everything that has come out. I saw these cameras (or something exactly like them) demoed at DTW a few years back, and I assure you, they are tracking everyone and everything. In that demo, a camera was watching a typical city street. AI was identifying people via face scans, scanning license plates, analyzing their movements, and then making recommendations about potential illegal activity.
And here's the biggest problem: They're SUPER easy to hack.
Video where they hack one in 30 seconds.
Somewhat related? In the wake of the NBA Finals,
someone posted all of the captured images from Madison Square Garden. It was tens (hundreds?) of thousands of people and even included information about each attendee.
This is going to sound weird, but in a high trust, free society there must be the ability to have privacy, and honestly, do something wrong. If there are cameras watching your every step, and all but physically preventing you from even littering, you're not free.
“Activism is a way for useless people to feel important, even if the consequences of their activism are counterproductive for those they claim to be helping and damaging to the fabric of society as a whole.” - Dr Thomas Sowell