Why should we be interested in random number generators? 
They're not covered in the text. (Maybe that's one reason.)

We use them a lot and we should understand their philosophy,
implementation, efficiency and limitations.

They are much applied to other algorithms, for example
  to test algorithms
  in "Monte Carlo" estimation
  to obtain a random pivot in quick sort, thereby avoiding (prbabalistically)
    the degeneracy for nearly sorted lists
  to obtain random pseudo primes in RSA encryption
  in "Las Vegas" algorithms
  to bust up potential deadlocks or cycling in operating systems
  in "genetic" algorithms