Because it's my image, and I should be able to exert a reasonable control over it. When someone publishes my image, I lose that control, and in these days that could mean anything, from people ignoring it to people making a meme out of it. And I also I shouldn't have to justify why do I have a right to control my own image.
> I feel like if you carry the argument far enough, then this should extend to satellite imagery of your home. Isn't that an equivalent violation of your privacy?
Yes it is. Luckily published satellite imagery doesn't tend to have enough resolution to actually make out distinguishing details of what would be going on in my backyard, but I'd actually be angry if they did.
> What about traffic cameras and other webcams setup in public places for public consumption online?
Luckily again, those usually don't have enough resolution to make out identifying details.
> If I have an equivalent right to photograph in public,
You don't. Privacy trumps your right to photograph in public. If you feel I'm making a funny face, you don't have the right to make me a photo.
> then it's an undue burden on me and a probably an even greater violation of your privacy to chase you and everyone else down and ask for the rights to reproduce it online
Asking for permission is not a violation of privacy.
> I'm not sure this is a feature I want to add to our public spaces.
The solution is easy: then don't make photos where people are identifiable without their permission. The alternative is you do, and imagine that you post it and someone makes a meme out of someone that appears there. How would you feel about it? Would your opinion change if someone came to you and said "hey, remember that photo you published where I was on it? Well now I'm the laughing stock of half a million people".