I don't think you know the history of Christianity enough to get my references. The biggest deal in 1100 was the Great Schism--no individual rights or other signs of individualism, no democracy, no separation of church and state, no rationality; pretty much nothing that we associate with modern Western values. The Great Schism was roughly a "states rights" issue, in spiritual guise: is every church "the church", or is there one church (i.e. the Catholic church)? The divine right of kings was pretty widely accepted; the idea that God would not wrongfully allow a victory in a duel was not without challenge from the church but also not particularly strongly disputed.

This date was chosen intentionally before Aquinas whose ideas were heavily influenced by wisdom from the Greeks and...from...Islam (e.g. arguments from al Ghazali). In Aquinas you start seeing far more echoes of what Western values would become, but again, a lot of those were inspired by similar thoughts by Islamic philosophers.

So the idea that Christianity is somehow fundamentally a unique wellspring of Western values contradicts the history of the West. It's perfectly well compatible with pretty deeply non-(modern)-Western values too, and given that at the twilight of the Golden Age of Islam, Islam in practice was arguably a lot closer to modern Western values than Christianity was at the time, there seems little reason to suppose that save for various accidents of history that Islam is necessarily the incompatible one and Christianity is necessarily the compatible one. Rather, our conception of what Christianity entails has co-evolved with values in the West.