It would be impossible to unite against Christianity or Judaism in Arabia following the Roman destruction of Jerusalem. Anywhere between 10-20%~ of the Arabian peninsula was Jewish and south of the
Ghassanids, perhaps 5% Christian; although very rare.
Both of these groups were essentially indigenous to Arabia by the 5th century. Judaism had only a small stigma before the periods of Islam, this is mainly due to a small sense of kinship between the groups as very close relation in language and a common history of resistance to more powerful near eastern societies. Some major cities too where primarily the possessions of Jewish tribes which oddly, followed modified Arab customs. Even famous cities such as Yahtrib/Madinah had powerful Jewish presence with an imposing Jewish defensive compound.
As well, it should be noted that the Quyaish at times had a more favorable opinion of Jews in the Hijaz than that of neighboring Arabs and their own Arab subjects. The distinct issue with Jews was their religion and some of their customs. Worship of one God however, was not extremely taboo for the Arabs, just In their opinion, wasteful. After all, the taboo in worshipping one god never existed in the Arab people until Islam; however, the Arabs did see Allah as the primary god and worshipped many, many more gods as intermediaries of Allah. Jews by the time, according to the earliest Muslim accounts, where apparently seeking a prophet in Arabia; this would correspond to certain Jewish teachings regarding the diaspora taking Judaism to the world seeking a messiah. This sort of messianic search, might have had an influence on the eventual creation of Islam.
Take note, antijewish (antisemitism makes no sense, whenever Arabs are also Semites) sentiment in Arabs only began after Islam and waxed and waned over the centuries. However, a constant was the Arab view of Jews as being honorless or cowardly; this sentiment did not exist before Islam.