I tend to think that many of us do live in multi-cultural societies with different religions. Rather than argue and disagree over cultural religious symbols creating divisions and tensions, conflict, I think we need some sort of symbol that represents all religions (as an example only :- Dove of Peace) and upon which all religions can agree (if indeed we can!) and which would become a social norm - while we do treasure our own Christian symbols and especially a crucifix and that they are displayed wherever Christianity settles and is the consistent cultural norm, such as Churches, Schools, Convents, Monasteries, Christian homes and hospitals etc. etc.
Doubtless an atheist might well have big problems with even a religious symbol that represents all religions, while the Dove of Peace would embrace athiests also, to my mind, who indeed also died during 9/11.
I also think that probably there are perhaps many that feel it is either " my way or the highway" instead of looking beyond divisions, transcending them, and looking for where we can agree and what might unite where cultural religious symbols are concerned i.e. searching for reflections of that unity for which Jesus prayed to His Father so ardently before His Passion - and after all, for us Christians for example, the dove represents The Holy Spirit and the olive branch represents “My Peace I give to you” (“I and The Father are One”)and I am sure that other beliefs can attach their own meaning to some generally agreed symbol.
Dove of Peace is an ancient symbol: learnenglish.britishcouncil.org/en/magazine-articles/peace-symbols