I don't understand it either. My guess would be that with the various ownership changes of rights to the Motown label over the years, there is probably a lot of litigation keeping it off the shelves. How great would it be to have a couple of two-hour DVDs of Motown acts in their prime?
Check out this Brenda Holloway song.
http://www.npr.org/programs/asc/archives/asc24/index.html#holloway
It's a real shame that NBC and Motown (depasse) did the TV movie on the Tempts portraying Ruffin the way they did.
http://laws.lp.findlaw.com/6th/01a0345p.html