Supposedly, after Samsung released the Samsung Galaxy NotePRO and Samsung Galaxy TabPRO tablets, Google called Samsung into the principal's office and told the manufacturer to tone down the modifications to Google's mobile OS. It seems that the powers that be at Google were upset with Sammy's Magazine UI because of the Windows-esque look the UI offers. Additionally, the UI cannot be turned off by users.
Most owners of Samsung devices aren't interested in the company's bloatware, and the Samsung Galaxy S5 did not come with Samsung Hub installed out of the box. Berne, for his part, isn't sure when it will be officially killed off. Until that happens, users of future Samsung devices will probably have to download Hub on their phone or tablet, if they want it.
source: SamMobile via TechRadar