I think that Jose makes a solid case that static typing doesn’t bring as much to the table to Elixir as most people believe, but enough people point to the lack of it as a reason not to adopt the language that it’s worth addressing. Again, I think @spec is great and people should use it more – just treat the dialyzer warnings as errors.
From reading that post, it sounds like Jose does not believe static typing is needed. But a nice to have to address a very narrow set of use cases that primarily would help for documentation, not bug mitigation.