Satisfying Needed Scope Versus Wants

What is the definition of Requirements Traceability Matrix? It's a table that links requirements to their origin and traces them throughout the project life cycle.  Not everyone uses them. There are many templates and means to ensure your project meets the requirements.  But I can't stress enough how important it is to ensure you're working to satisfy the requirements (or scope) first.  I reviewed a vendor's progress report today and realized the very last task they had on their activity list was requirement mapping.  When asked why it was the last item on their list, their response was the activity wasn't on the critical path.  So, how on Earth were they going to know they were done, if they didn't map the requirements first?  Here they are, at the end of a development cycle, and we're being told the requirement mapping activity is just basically a clerical process. Imagine the frustration I suffered, knowing all too well they may have missed something.  Imagine how expensive it could be, to fix at the end versus the beginning of the development cycle?  I'm not saying the vendor didn't do a lot of work or deliver a lot of product.  Unfortunately, they spent way too much time satisfying the daily wants of a stakeholder and took their focus off the needs of satisfying project requirements in the process.

What do you think?  I'm a being too much of a control freak?