According to harold garfinkel and ethnomethodology, people tend to get upset when minor conventions of talk are not followed. his explanation for this reaction is that:

The reason that people usually will be bothered by the absence of conventions of talk is that in our communication lies cultural similarities and differences. When we follow conventions of talk, we are following our cultural norms and this provides a level of comfort for those involved. When these are not followed, there is an uneasiness that comes with the unfamiliarity, and necessary assumptions about the meaning of the communication can not be made.