You can churn out a greenfield project faster as you don't have to spend upfront time mapping out interfaces, DTO's etc. It's also easier to 'hack'.
Of course the above makes the code harder to maintain and reason with, unless written by very disciplined engineers.
So these languages are a natural fit for startups (and things like prototyping and scripting).
Instagram would have been in this category, and it's worked out well for them.
You can churn out a greenfield project faster as you don't have to spend upfront time mapping out interfaces, DTO's etc. It's also easier to 'hack'.
Of course the above makes the code harder to maintain and reason with, unless written by very disciplined engineers.
So these languages are a natural fit for startups (and things like prototyping and scripting).
Instagram would have been in this category, and it's worked out well for them.