Why are we Americans not thought well of?

I have a few European friends as well as a few from other cultures.
They say to me that their poor view of American people is due to obnoxious tourists who are loud, intrusive, largely overweight, wear horrible "loud" clothing and are just plain rude. I cannot argue with that view as I have seen this type of person myself. Just take a look at that "people of Walmart" web site and see for yourself. Yikes.
They also form opinions based on the TV shows that are imported to their countries.
Look at the shameful things they send over.
Why do many of the TV shows have to be "naughty" in order to be entertaining nowadays? So, if you see a movie or show that depicts people as low class, with bad morale behaviour, violent, swearing all the time, etc. what will you think of the society? We appear shallow and I think we are, in general.
I think we need to take a long serious look at what we portray ourselves to be to other countries. I am certainly not proud of my country. I don't think other countries envy us at all, I think they are disgusted.
There are many things to be proud of here in the USA, but we are not putting our best foot forward and showing other societies what we are truly like, sadly. I think we need to work on this.