> I have reluctantly come to accept the fact that somewhere up there, in the vast expanse of primes, a cluster sits there outweighs the first chunk of prime numbers.
Just because it is possible doesn't mean it exists. Of course the odds of finding one are negligible so we'll probably never know for sure.
The author is making the following reasoning: Conjecture 1 and Conjecture 2 can not both be true. Conjecture 1 is believed to be true. Therefore Conjecture 2 is false, which implies that there must exist a heavy cluster of primes out there.
Just because it is possible doesn't mean it exists. Of course the odds of finding one are negligible so we'll probably never know for sure.