Tizen has always been intended to be for their low end phones for developing nations,but I can imagine Samsung likes to have Tizen in it's back pocket in case Google gets too "pushy" in it's requirements for Android licensing! There is a good reason Samsung is spending so much money developing TouchWiz, all it's own, apps, services and app store! Sammy could switch to Tizen on any phone it sells and most people would never know it! You would be using the same TouchWiz and just be clicking into the Sammy store instead of the Play Store!
While I'm sure this will spur ALL kinds of debate, how big do you actually think Android would be today if you take Samsung out of the picture the last 3 years!? Surely much less then the 50+% it has today!
And keep in mind, the vast majority of users are going into the store buying Galaxy phones...NOT Android phones!
Cheers