Emil clarifies that it’s while it’s important to prepare as much as possible, it’s dangerous to jump in and start building CMSs and frameworks without knowing what the project requirements are. Developers have a tendency to get a bit too excited about New and Shiny Tools, and that can be dangerous.
I agree completely, and I suppose it’s worth noting most projects I’ve worked on have included high-level tech requirements in the proposal and statement of work. Usually I know before the project kicks off that the organization is migrating to WordPress, or that an e-commerce site will be built in Magento. It’s important to have the right up-front discussions about what technologies, platforms, and tools will be important to the success of the project.