Also, this new BBA SACD may not be cheap in the scheme of things but the DTS CD isn't that cheap anymore, making the new SACD all the more welcome!
That said, I'd rather Sony do a Rough & Ready Quad SACD next than revisit any other DTS CDs etc but still..!
I completely agree with you (and the same for Wired) but I think the stuff definitely already exists in digital form (ie previously released on DTS CD) is probably the lowest-hanging fruit (ooh la la) for Sony to release. So Blow By Blow sold well enough to lead to this BBA release, hopefully this BBA release will sell enough to lead to something else, and so on.
I think there is some reason to be mildly hopeful about 'fresh' quad SACDs from Sony Japan, though. They've done some classical SACD reissues (the 2007 Bernstein/Mahler series comes to mind) of old Columbia Masterworks titles that have the quad mix on the multichannel layer, and those are the first/only digital issues of thos quad mixes. So there doesn't seem to be any technical/technological/finanical impediment to Sony Japan doing 'new' quad reissues.