I think the point is that you can ease in to that with PHP - you can be as dynamic or not as you want. Many (many!) people started with PHP just to add a contact form to a site, or make a dynamic copyright date in a footer (or just to do common footers with include()). Rails/Grails/Play/CF/etc assume you want to do a lot more, and force you to do things their way - integrating a tech in to an existing site is really problematic outside of PHP, because most other webdev tech is 'full stack'.