It's about efficiency. How much time was wasted assigning the wrong value to a variable. Having accurate variable declarations are about gain in efficiency. It's about readability. It about following the existing patterns. If you want creativity, do user interface design, do system architecture. If your programming, it should be designed to make you team members job easier: not yours. A 2% gain in efficiencies is an extra week each year. That's 40 hours gained. Human productivity gains are made by compounding efficiencies.
