It's not totally divorced from the static vs dynamic argument. One of the main arguments people deploy for dynamic typing is that most type declarations are boilerplate and take time to code but don't add any value. But the reality is that they do add value because they enhance the readability and maintainability of the code (and this is one reason I'm not even a great fan of type inference in many situations). So it comes back to the value of maintainability vs getting your first iteration of the code to work.

It's also caused by the fact that nowadays a lot (most?) of the code that gets written is for the web or mobile, where technology changes incredibly fast.