You rooted your phone and have the nerve to complain that the vendor won't let you install their official upgrade? You think they should test it on all possible configs of rooted phone? You think they want people coming to them for warranty service because they rooted their phone and Samsung's upgrade bricked it?
Why didn't you just install generic Android and be done with it, why the desire to use Samsung's build or go to all the trouble to shut down their software? You could simply have installed generic Android and be able to upgrade immediately it is available rather than wait around for Samsung.