Is "vocals" your definition of professional music? It's not mine, at least. And I do also use MPT for "bigger" projects, mind you. Still, this is not a justification for including 10mb of demo songs when the program itself is about 1 megabyte in size. You oversee that demosongs are mostly for beginners, and I doubt that anyone starts with MPT as a "professional". Those have to climb up a long ladder, and once they're up there, they don't care about demo songs anymore, so they don't have to be super big for them as well. They will maybe rather be surprised what kind of kick-ass music you can get out of a few kilobytes. Listen to
this, for example. It is made by a "professional" who still (again) uses ProTracker (!!!) for his live-sets. And they do kick ass, I've heard it myself. You don't need gigabytes of samples for professional music, you can get awesome sound out of a few kbytes as well.