> It may be the case that we have cut our
> abstractions too high to take advantage of some architectural features
> present in modern microprocessors -- it may be that we want to allow

I might draw a different conclusion.  As with some peculiar memory subsystems,
botched device interfaces, or 80 core processors, I'd say that perhaps the architectural features are there
to meet the needs of hardware designers and are not actually designed to run the programs
people are actually writing.  Perhaps someone told them the software people wanted
some of this stuff, but I've got my doubts!