On the other hand there may be some startups where the choice of language really matters. One thing I can think of is how a lot of Enterprise software is a big feature fest with massive complicatedness coming from a mixture of the real-world muckiness of the problem, and poor architectural choices. Such shops require armies of programmers to maintain their bloated wares. Maybe a startup with a much more thoughtful approach, using a Lisp/Haskell/etc. type language and a small number of developers can have a big competitive advantage.
Customer "we need a new feature". Startup "sure we'll add a rule and you'll have that tomorrow". Old business "that will take 3 months and cost $1m"