'These people'

Have you ever come across the usage of the phrase 'These people'? I have come across this quite a number of times, and everytime it kinda sounds derogatory (not sure if the speaker intended to...). More importantly, I am surprised when I hear it from two groups of people refering to each other (obviously in different conversations)!! For example, today I heard my friend, who has come to US recently from India, asking me if 'these people' (americans) have 'bread' for all the three times in a day. I immediately remembered one of my US colleague asking me if 'you people' (Indians) have 'rice' all three times a day!! One might think it is because of the so-called vast difference between the cultures...no, its not the case! I had the same case between North and South Indians (obviously, this time it was between 'Roti' and 'Rice').
Don't 'these people' recognize their habits and behavior before asking questions about 'the people'???