Form Equals Function
Another problem with "form follows function" is that it implies a one-way causal relationship between function and form. But we could just as easily flip the phrase and assert that "Function follows form." For example, once I design the form of a doorknob, that form now determines the way in which the doorknob functions in the world. Form and function are causally interchangeableneither follows either, or both follow each. Or perhaps form and function are so contingent upon each other that they are practicably inextricable.
Perhaps we need a new formula: "Form = function." This equation is particularly true on the Web, where "architecture" is entirely virtual. If your web buttons "look and feel" formally clunky, they actually "function" clunkily. Rather than designing forms that follow a frozen, modernist understanding of human function, why not invent forms that drive and evolve better ways of human functioning?