This is a fallacy. Chistianity is a universal religion in the same sense as the Chinese used to think their civilization was universal. In other words, it is seen as the only true one, but applicable to all peoples and countries. It is not about being able to accept all things, but rather being absolutely true and relevant in all contexts and settings.
Buddhism and Christianity are both universal in their claims, but the fundamental difference is that Christianity is centered on monotheism, while Buddhism is not. This gives Buddhism a much bigger room for maneuver in accommodating other beliefs - for example to see them as partial manifestations of the Buddhist truth.
I am not going to make this a religious sermon, well aware that many other forumers may not be Catholics and Christians. The days of the inquisitions all long gone. Yes, Christianity is centred on monotheism, but Christians recognise their monotheistic premise of "our God is the one and only God" is and will cause much friction in their relationship with non-believers. Christians believe that God must have His reason in allowing other religions to exist. We may not believe in what the Hindus, Buddhist etc believe, and we may not agree with their symbols and motives, but they are there, and we accept their existence. Hence, I find it extremely annoying when people start having medieval thoughts of symbolic incompatibility and its resulting spritual disturbance.