The cops cannot be held accountable because the laws basically give them immunity. The politicians cannot be held accountable beyond being tossed out at the next election, because the laws otherwise give them immunity. The people operating the system cannot be held accountable, because the systems are marketed as authoritative despite being black boxes and lacking in transparency; they trusted the system just as they were told to, and thus cannot be held accountable.
And so when every human in the chain cannot be held accountable for these things, and the law prevents victims from receiving apologies, let alone recourse, then the tool and its maker is the only thing we can hold accountable. By deflecting blame away from the tools ("it wasn't AI, it was facial recognition"; "the human had to sign off on it"; "humans made the arrest, not machines"), you're protecting quite literally the only possible entity that could still potentially be held accountable: the dipshits making these stupid things and marketing them as superior and authoritative when compared to humans.
You want accountability? Start holding capital to account, and this shit falls away real fucking fast. Don't get lost in technical nuance over very real human issues.