“The nature of Bitcoin is such that once version 0.1 was released, the core design was set in stone for the rest of its lifetime.”
– Satoshi Nakamoto
But what defines the "core design"? Changing stuff which is not part of the "core" is ok then? Is the transaction ordering (ref CTOR) part of this "core" or is that part of the edge?
Unless you believe that Satoshi was an almighty god which could foresee all future development, I don't see why some optimizations cannot be carried out on the protocol.