Because they take exp(5) more time to read, you take logarithm to make it sound better.
Seriously, I see this quoted without context all time. They are domain specific languages.
I don't believe that. They are better at general purpose programming than regular languages. And I don't think they take longer to read in terms of distinct operations.
Do you have any code examples of array languages being used for general purpose tasks? Clis, web applications, anything with lots of branching, games, etc?