To an implementor, isn't one of the biggest differences between DH (super easy to implement) and RSA (considerably trickier) the difference between needing one prime number instead of two?
Anyways I take your point. The paper really doesn't have too much to do with the title.
To me, the biggest difference between DH and RSA is that DH is stateful and RSA is stateless. Next up is that with DH you're generating random exponents each time instead of doing it once during key generation.
The number of primes involved is way down on my list of important differences between DH and RSA.
Anyways I take your point. The paper really doesn't have too much to do with the title.