Abrogation of Kashmir's special status has been a top agenda of the BJP for the past few decades. They are pretty big on "national unity", and they see the special status for Kashmir as going against this principle. They want Kashmir fully integrated into India once and for all. They also consider the indecision about Kashmir's status in India as being a prime cause for terrorism in that region. Kicking the muslims has very little to do with it.
Whether this step will backfire remains to be seen. Indians will have to ask some very tough questions about what kind of nation they want India to be, and whether the vision they come up with will be viable at all given the nature of the Indian society.