Why did Muslims stop eating pork?

Reasons for Avoiding Pork in Abrahamic Religions

Within the context of Abrahamic faiths, the consumption of pig meat is explicitly prohibited by the dietary laws of Judaism (kashrut), Islam (halal), and certain Christian denominations such as the Adventists (kosher animals). In both Judaism and Islam, pigs are regarded as unclean animals in terms of food, and this belief is also reflected in some branches of Christianity.