And half the reason we keep throwing code away is because it was created without consciousness of maintainability.

Well, this has nothing to do with static vs dynamic typing. You can write unmaintainable code in static languages very easily. In startups, developers often overlook maintainability, I completely agree but that's because everyone knows that the code you are writing today might not be needed 2 years down the line, you are mostly iterating to find PMF.