I've been writing code since the 80s, professionally since the mid 90s, in almost every major language, platform and operating system, from 8 bit microcontrollers to large scale web platforms.

So, not sure that counts as "serious" in your estimation, but I would definitely argue that dynamically typed languages are superior for a large class of problems.

Also, just a tip: it's usually better to be less sure of yourself, and seek to understand other's reasoning. It'll get you a lot farther than trying to convince everyone of how right you are.

If you're not sure why an experienced developer would hold an opinion different than yours, why not just ask?