According to Muslim historians, the Meccans were actually quite tolerant of Muhammad preaching his new religion.  Mecca was an open society where different religions were respected.  Polytheists, Jews and Christians lived and worshipped side-by-side, especially during the holy months, when pagan pilgrims would travel long distances from beyond the city to perform their rituals at the Kaaba.

Muhammad brought on the resentment of the local people by breaking with tradition andcursing other religions:

When the apostle openly displayed Islam as Allah ordered him, his people did not withdraw or turn against him, so far as I have heard, until he spoke disparagingly of their gods.  When he did that, they took great offence and resolved unanimously to treat him as an enemy. (Ibn Ishaq/Hisham 167)

Reference:, The Myths of Muhammad