Yes I don't want to work for a startup and I stated as much didn't I? ;)
What it has to do with Elixir is that Elixir does not scale well with a number of programmers, and many startups go through periods of explosive growth of personnel. With Elixir that very rarely works well, 99% of the time IMO it does not. Adding more people does not increase productivity, it hurts it even.