My mother doesn't know what that is or its use. Neither does my brother, sister, neighbor, dog, ipad, etc. So I'd say only geeks know what a feed is. Then let geeks use an extension and don't bother +90% of internet users with that. It is in a sense like developer tools, if you know where they are you can easily activate them and use them, if not, they are out of the way. Good riddance.
Now in the good spirit of a designer in search of a solution to everything and everybody, add an option in preferences to show/hide the feed button. How about that?
Edit: Some are claiming that you can still add the button to the toolbar, it’s just off by default. That sounds extremely reasonable and confuses me at the same time because I don’t understand what all the fuss is about.