Of course it is welcome to have a responsive theme that transforms accordingly for mobile users who are using smartphones or tablets and users with small screens in general. But personally I feel that I don't want websites to transform when I'm using a big screen. I want only one version for the screen that I am using. I may want to isolate certain areas and view them simultaneously in different minimized windows, I may like to minimize the window without seeing the website changing (apart from the containers expanding/collapsing and the text wrapping), I may be sadist and love the horizontal scrollbar.
It usually comes down to how well a particular website is using the responsiveness. I've seen many websites which remove whole sidebars and append them below the site's content and that do many other ferocities

PhpBB does it right, but still I may want to define how my website will look based on a min-width and/or a max-width without changing how it looks (again, containers expanding/collapsing and text wrapping are fine).
So place here your ideas in favor of it or against it and let's discuss how it could be implemented if you think we should have it.