Forms of greeting vary from place to place. The comfort level towards a form of greeting depends on the upbringing and sensibilities of a person. For Muslims, their sensibilities are shaped by their faith. Like we expect a foreigner to respect our sensibilities when they greet us, we too should respect the sensibilities of our fellow Indians.
Muslims do not eat “Prasada (Prasadam / Prasad)” because of their ideological position. This is very similar to the ideological position of vegetarians who would refuse to eat non-vegetarian food. The yardstick used and the consideration given for the Vegetarians must be applied to Muslims also.
Simple answer to “Why Muslims eat non-vegetarian food?” is because Muslims believe that “God has allowed eating non-vegetarian food.” Muslims believe food choices are very personal. Individuals have their own diet preferences and these preferences must be respected. It is not correct to judge those who do not share our diet preferences.