TABLEs for layout is materially dishonest. The
TABLE element is intended for marking up the structure of tabular data. The end result of using
FONT elements, and spacer GIFs is a façade. At first glance everything looks fine, but it won’t stand up to scrutiny. As soon as such a website is stress‐tested by actual usage across a range of browsers, the façade crumbles.
Using CSS for presentation is materially honest—that’s the intended use of CSS. It also allows HTML to be materially honest. Instead of trying to fulfil two roles—structure and presentation—HTML can return to fulfilling its true purpose, marking up the meaning of content.
[About mobile first/responsive design:]
This content‐out way of thinking is fundamentally different to the canvas‐in approach that dates all the way back to the Book of Kells. It asks web designers to give up the illusion of control and create a materially‐honest discipline for the World Wide Web.
From Jeremy Keith: Resilient Web Design