Comment by pclmulqdq

Type systems and type-based coding patterns are very hip right now, but they weren't 6 years ago. That is partly because the type systems in the main languages in use 6 years ago were hack jobs (to put it politely).

I do expect the pendulum to swing against type systems at some point soon for the same reasons it swung against OOP: Too much heavy lifting done by something that's hidden from the programmer, encouraging people to be "too clever," etc. Like OOP, algebraic types are a tool that have to be used well, and the current users are people who really like type systems and do use them well. It's only a matter of time before the tool gets into the hands of the average programmer, and then we will see how terribly a great type system can hurt you.