Earlier quoted context omitted.
> you are subjected to browser width text Some of us consider it a feature that a website allows the reader to freely resize the browser window (and the text with-in) to the width they consider comfortable.
So if you want to use for example maps on one tab and read text on another, the best UX would be to have users resize their browser when changing tabs? There are few reasons why a line of text should be longer than, say, 800 (css) pixels, but having the browser full screen might still be a good idea for more app-y sites.
But I agree that I commonly see people having their browser window maximized all the time (on huge monitors, to a great waste of on-screen space). I think the fact that they became accustomed to that is an unfortunate consequence of modern web design.