But that is just the first step. You then need developers who write applications on top of those languages be multi-core aware and design their applications to fully use the huge number of cores. At that point you'll loose a lot of your power efficiency because you'll need a lot more hardware running to do the same tasks. You'll also need developers who know how to think in an extremely multi-core way to get the extra performance boost.
RPis are built to a price and don't have the best CPUs that ARM can offer. A better comparison would be Apple's A chips.