It's not exactly about the privacy in public, though. YMMV, but I'm 101% fine if a camera looks at me and a machine processes the image. What matters is what happens afterwards.
Heck, I want an aid like that - my built-in wetware face recognition is barely functional (I don't even recognize actors in the movies, save for a few most iconic ones), and tying faces only works after repeating it a dozen times. I can pinky swear I won't be sharing this with anyone. I probably won't even keep records, because it's literal digital junk (but I'd like to have a right to record everything that happened around me that I could've possibly remembered naturally). But that's not about it - I just hate how mass surveillance made a lot of people hate all the cameras without making any distinctions (sure, I think I get it).
What this is about is that while individual privacy in public is not expected (save for stalking or other forms of harassment, which aren't exactly about privacy anymore), privacy at scale is an open question. Large entities, like governments or big companies, can collect unprecedented amounts of data, and at that scale it holds a significant potential both for good use and for abuse. So, in a functional democracy, it must prompt a public discussion and search for a consensus. It can be argued that there are benefits, and whenever benefits outweigh the risks, and it also can be argued that old principles must be still upheld to the letter, or if reality had changed too much and those principles are not matching to the ideas and reasons...
It especially matters when it's about the government, because government abuse can get really nasty, even deadly. That's why all the safeguards, checks and balances.
Basically, I think it's not really about cameras, it's about ability to build large databases with information that may be, uh, socially sensitive.