People read best when they don't move their head left and right. This means 80 characters in a line. Why must CSS frameworks have support for being "responsive"?
Why is responsive good?
Text growing to fill the width of the page is the default mode of the web. The ability to control the width of text came much later. What has only recently become practical - and what people mean by "responsive" or "fluid" layout - is the ability to intelligently reformat the page to suit the available container, by for instance using a layout that can grow from a single column to five or six columns depending on the container width, or by removing or simplifying certain navigation elements in very small containers.
Designing around a fixed layout is a very bad idea. Viewers with smaller than anticipated containers will have to scroll horizontally and users of wider than anticipated containers will be frustrated by large areas of whitespace. Your layout is liable to break completely if a user is substantially altering your page layout, for reasons of accessibility or convenience.
Responsiveness is about designing sites that are maximally readable and usable on all devices; When done well, sites will effortlessly adapt to new devices and new form-factors.
The main argument I see against separate "views" is that it's an expensive exercise to effectively build two frontends for a single site. However, as someone who has built both large-scale responsive and mobile-specific sites neither is really cheaper.
Why can't you have only one version, and someone on mobile will zoom in and out?
A web site version with 10 things on the header is going to piss people off on the mobile app regardless of how responsively those 10 things show up in their face. A better thing to do is to not show any of those crappy 10 things to begin with.
Because to do that manually is usually clunky. Responsiveness makes it happen automatically and thus smooth.
>A web site version with 10 things on the header is going to piss people off on the mobile app regardless of how responsively those 10 things show up in their face.
Good responsive sites rearrange those 10 things in the header so that they are not "in your face" as you say. See also: Twitter Bootstrap.
Twitter Bootstrap has been a disaster for me: http://news.ycombinator.com/item?id=4651506