A better way of stating it, is that while Lisp is older, there is a lack of real world experience, documentation, and support for using Lisp as a language for web development. The volume of material, understanding, and optimization strategy for PHP is far and away greater than Lisp.
As an example, search for a simple question on how to do some developmental task on google for both PHP and Lisp. PHP will have more informative pages.
As an example, search for a simple question on how to do some developmental task on google for both PHP and Lisp. PHP will have more informative pages.