I think it's a political thing. Europeans tend to be more Marxist (i.e. "left") and history-based while Americans are highly influenced by the capitalism of Ayn Rand et al.
Leftish people believe in a big government that takes care of the citizens. The standard rebuttal to this is that it's naive and people will exploit the system. Socialists also TEND TO BE less eager to go to war, so that might be taken as weak or cowardly.
Also, Europe countries have (mostly) longer histories then the USA does, so there often is a traditional "ruling class". This might be seen as Elitist.
The Laisez-Fare capitalism of the US believes that citizens should take care of their own business. Opponents see this system as narrow-minded and stupid (They took our Jobs!). Americans tend to be rather aggressive in their foreign policy, which Europeans sometimes see as arrogant: they get the impression that the US wants to make the entire world American. And who are they to say their system is the best?
Note: I am not a sociologist or anything. And I'm European myself. This is mostly speculation, so if I'm wrong please correct me.