Why did the team at LMAX design the LMAX Disruptor in Java but all their design points to minimizing GC use? If one does not want to have GC run then why use a garbage collected language?

Their optimizations, the level of hardware knowledge and the thought they put are just awesome but why Java?

I'm not against Java or anything, but why a GC language? Why not use something like D or any other language without GC but allows efficient code? Is it that the team is most familiar with Java or does Java possess some unique advantage that I am not seeing?

Say they develop it using D with manual memory management, what would be the difference? They would have to think low level (which they already are), but they can squeeze the best performance out of the system as it's native.