Why was it an issue?

Religious discrimination in Christian Kingdoms

As we have seen, the ruling elites of the Christian Kingdoms of the Iberian Peninsula, became openly hostile towards Jews and Muslims during the 15th century. More restrictive measures and new taxes were imposed on these communities, their legal rights were ignored or violated and the growing discrimination ultimately led to the confiscation of property, tortures, forced baptisms and, finally, expulsions.

In your opinion, was this a sudden change of position by the Christian rulers or was it the result of a longer process?