That's well and good, and it's genuinely always nice to hear about musicians pushing for proper mixing and sound engineering.
However, his "manifesto" is still a load of poorly-informed twaddle that assumes that everyone in the world has the same resources as he does; which, given that he's an internationally famous musician with a number of well-received albums and singles to his name, strikes me as somewhat unlikely. Sadly, not all of us have the time and cash to be able to buy everything we need or want exclusively through local suppliers. Through internet forums I've found more friends who share genuine interests and outlooks with me than I've ever found through traditional social outlets; I've also found far more about niche bits of culture (be it film, books, comics or music) in which I'm interested which it's vanishingly unlikely I would've found through normal retail chains. So dismissing all of it because some consortium of retailers asked him to be their poster boy is, on the face of it, not a move that deserves much response beyond "that's nice jack, now piss off ".
I'm all for serious discussion about the future of the local retailer, but Jack's twaddlefesto is not the way to go about starting such a discussion.