The overall point is valid -- having a lot of users is the main way that a lot of companies make/want to make money, therefore companies should focus on scaling issues, therefore... "use Erlang."

However, conflating Web 1.0 "get fast" with Ruby on Rails "develop fast" is:

1) wrong: with extremely limited resources and a long list of priorities, startups need to start with fast, basic tools in order to get a functional site up -- to then discover what people want to use. scaling comes later, if ever.

2) self-serving: this guy seems to be intent on getting more companies using what he has to offer

Conclusion: mind the hyperbole.