To increase brand value and exposure, as they did with Monaro.. Everybody loved the Monaro (as well as VX220 infact). They were cars to help you forget the mid 90s disasters that were Vectra, Omega, Frontera etc for reliability and customer satisfaction..
Plus, Commodore is only coming here as a HSV version, can't remember which! Its basically the flagship of the brand to raise enthusiasm and target a customer base that would definitely not have looked at Vauxhall previously! I only hope there aren't massive discounts like there were for Monaros after a few years over here as this, whilst good for someone like me who wants a lot of car for little money is unacceptable to someone who has just invested £30k on a brand new niche car only for it to be work 50% in 1-2 years