Quite right! Not sure if it's just Ian Anderson or more Chrysalis/ Parlophone that has such an allegiance to Ray Shulman as the authoring person for these Jethro Tull releases.
Does he really do a bad job on these? No not really. As a matter of fact, I liked his work particularly on "A Passion Play" and even "Thick as a Brick" but the fact is if you're not going to have some kind of substantial video component, it really should be DVD-A, not DVD-V, and that's where these releases miss the boat...
Maybe one day when Warner goes head first into Blu-Ray audio and surround, then we will get these as full lossless but for now I will enjoy them as they are. Despite being DVD-V, they are far and away very high quality products.