I agree that a shrinking percentage of society is doing agricultural work, and certainly many specific tasks of grunt-work-of-yore are less grunt-y and more automated.
But my assertion was not that "automation has not started doing any of the grunt work we once did". My assertion was that the segment of society that WAS doing grunt work is mostly not elevated out of grunt work TODAY. I assert that, rather, those people are mostly either still doing grunt work, or else are unable to find a useful role in society (a leftier turn of phrase would be "they are being abandoned by society"). I can certainly concede that there has been SOME improvement in this, but it's vastly less than starry-eyed optimists seem to suggest.
Remember that this followed mwd_1 stating a vision of the future, in which "humans are freed from the grunt work they do now", by which I assume (s)he meant not just today's variant of grunt work, but grunt work in general. Basically, my whole claim is that techno-utopianism is unrealistic, and it is unrealistic for social reasons, not technological reasons. Not that it stops me from wishing for it.
Oh, and a minor unimportant correction: the phrase is "grunt work", not "grudge work", at least in most English-speaking communities. Look it up.