The main idea, as I understand it, is that it's impossible to determine if there is global rotation without being able to observe everything, so the question of whether there is net global rotation is scientifically meaningless because it's impossible to answer.
Local rotation of a frame on the other hand is measurable without referring to observations of objects in other frames.
Reductionist and proud of it.
Being ignorant is not so much a shame, as being unwilling to learn. Benjamin Franklin
Chase after the truth like all hell and you'll free yourself, even though you never touch its coat tails. Clarence Darrow
A person who won't read has no advantage over one who can't read. Mark Twain