On Islamicate Societies

Regarding the new book, Islamicate Societies by Husain Kassim.  The concept is of course borrowed from Marshall Hodgson's The Ventures of Islam.  But I have always had a problem with the notion that all manners of change, or the reduction of Islamic ways so to speak can all be attributed to the "adoption of Western models".  Why is the distinction between the Islamic past and the Islamicate present is all due to the colonial impact? The concept requires a methodology to delineate those changes that were due to the colonial effects and those that are due to indigenous, homegrown factors.  That is all.