I get all that.... :upthumb
..though we don't get much surround music on the radio round these parts so it seems a bit, unneccessary to compress the beheck out of the 5.1 in this way..?
Yup. In this case it's just ignorant complacence. "This is how we've been doing it for years now." I can see no other plausible explanation.
It all has to do with CD remasters trying to compete with newly mixed and mastered CDs.
If you're a mixing and/or mastering engineer working with both stereo and surround mixes, you want the perceived loudness of both mixes to be the same, so if you compress and limit the stereo mix to a great degree, you'll have to do the same to the surround.
And that's probably what happened here. The surround mix on "Tusk" was compressed and limited in such a way to match the perceived loudness of the latest stereo remaster also on the disc.
I don't agree with how loud it is, but then again, they didn't ask for my advice…