Most people don't try to come across as rude — for whatever reason, they just don't realize how their actions look to others. That can lead to a rather rude awakening for them down the line, once they're confronted with the consequences of their conduct.
One of the worst places that you can come off as disrespectful is during a job interview. You want to charm and impress your interviewer, not turn them off with bad behavior.
Here are some particularly inconsiderate, alienating things to avoid saying in an interview:
11 things you say that can immediately disqualify you in a job interview
18 annoying things job candidates do that make hiring managers not like them
9 signs you bombed that job interview, even if it doesn't feel like it