The time of "las tres culturas" that they talk about was under Alfonso X, a learned Christian king, in a reconquered part of Spain.
In Islamic parts of Spain, things were very uneven. Some of the Muslims softened up after contact with Christian and Jewish cultures, but they themselves were then conquered by more "orthodox" Muslim tribes from North Africa and other parts of the ME. But in general, things were bad for Jews (even Maimonedes converted to Islam briefly) and worse for Christians.
The Christians won ~ was that bad for them to have done that?