Forget the "we need to protect our suppliers", and the "our aim is to create one of the strongest and most innovative automobile alliances in the world" hype coming out of Zuffenhausen.
The Porsche purchase has everything to do with Ferdinand Piech's obsession with bringing the two independent parts of what he perceives as the Porsche family companies together. You will remember that Piech is the grandson of Dr Ferdinand Porsche, who created the Beetle - and thus Volkswagen and the city of Wolfsburg – for Adolf Hitler.
After WW2, Porsche's son Ferry set up the Porsche sports car company, using VW mechanicals as a basis. As an engineer Ferdinand Piech first worked for Porsche on a new flat-6 engine for what became the 911. After it was decided by his mother Louisa Piech and uncle Ferry that no members of the by then feuding family should work for the sports car company, Piech moved across to Audi in the early 1970s.