It's disrespect and plain bad manners.
The end of good manners is the end of civilization.
"Manners are of more importance than laws. Upon them in a great measure, the Laws depend. The Law touches us but here and there, and now and then. Manners are what vex or soothe, corrupt or purify, exalt or debase, barbarize or refine us, by a constant, steady, uniform, insensible operation, like that of the air we breathe in. They give their whole form and color to our lives. According to their quality, they aid morals, they supply them, or they totally destroy them."
– Edmund Burke (1729-1797)