Implying that she killed a major character just because she didn't like her is doing Margaret a diservice. She made an editorial decision that she had to actually go to paramount and sell them on, including how it could be used to advance the whole of the franchise.
Ironically, just before people started reading and reviewing PAD's novel, there were several rather angry and dismissive threads on this board essentially saying, "When will Pocket Books and CBS Consumer Products ever grow the balls to kill off a major character - and keep them dead?"
Oh how the tables have turned.