I remember countless situations where I wish people clicked reply all and they didn't.
I remember a handful of situations where people clicked reply all when I didn't want them to.
One particular project I was working on had set very clear guidelines, if you were in the "to" field, then the email was for you to respond to, if you were in the "CC" field then the email isn't directed at you, rather it's for you to be aware of what's going on and for the recipient to be aware that you are looped in.