I obviously have no idea what goes on at Stern, but that said, I can't see how they'd win in any way by responding your emails.
Even a little "thanks for the feedback" note will immediately get posted here on Pinside. The language will get picked apart, the fact that there's any response at all will start a back and forth over what it means, should we be doing this for every game now, etc etc. There will be a thread for every game with people posting about how many different email addresses they're CCing ("emailed Dwight, George, Gary, Chas, and Bug Report").
I'm not saying don't do it, do you, not my problem what emails Stern deals with. Just saying, I can't see any upside to them actually responding. At best they'd talk internally and act or not, and probably never acknowledge any changes were in any way prompted by fan feedback.
My personal take though? Be nice about it. CCing everyone doesn't really help, and if people get at all entitled or jerk-like it's not helpful. When people want things from me and they act like a dick about it my easy response is to just toss their email into my spam folder. Dwight and the other people there are humans, try to stay kind.