Rudeness on Purpose?

Today I went with my family down to Chicago to see a German Christmas festival and to see the Nutcracker ballet. We normally go every year and now it seems to be a tradition. However we always know that at each of the ballet's performance there will be rude people there.

Laughter and full conversations during the performance occurs all the time. People pay good money to go to a show like this so it's not like it's cheap. Is it hard for some people to become aware that they are being overall rude? 

It could just be the culture of Chicago but it may happen to every place on Earth. Some people do it on purpose to piss people off for attention. But most of the time I believe that they do it because they do not think it is causing harm to others.

What do you guys think? Are most people rude overall or are they just pure evil? 

Thanks and Happy Holidays!

-NateStudios