Removing Abominations
There is a commandment in the Torah that upon entering Eretz Yisrael, we are to utterly destroy all places of worship to false gods.
The Land of Israel was given as an inheritance to the Jewish people. It is meant to be the place where Mitzvot are observed, and a close bond with Hashem is created.
Symbols of idol worship are clearly a blemish and detracts from this holiness. It is understandable, that it is necessary for the day to come, when such symbols would no longer exist.
The Rambam in Hilchot Melachim, has a section that was censored in many versions. He wrote that although it was clear that the religion of Islam and Christianity were false (this is why it was censored), he preferred that these religions be observed as opposed to paganism.
He felt that these two religions had a concept of Mashiach. This was important because it would make it easier for them to accept our true Mashiach when he comes.
Although it might be painful for us to see places of Avoda Zara in Israel, we must be patient and respectful of other religions, until Mashiach comes and removes all defilements in our land.