Ollie Onion,
Given it has been happening constantly for more than a decade I hardly think the "protests would be defending" as we are all pretty well used to it by now.
Of far more relevance though is the fact that the offloaded flying will still be flown by Virgin pilots. You wouldn't have heard any complaining if the Qantas guys were allowed to fly their own planes on their old routes under their usual award even after the jets got a new paint job.
Looks like their are 2 ways of skinning a cat and one way avoids infuriating your employees, but that tends not to be path Qantas choose. I'm glad to see Virgin have take the other path.