Maybe it has to do with having a basically 2-party system. That tends to polarize. Those not in power tend to feel disenfranchised and resentful.
Minority governments on the other hand, tend to build consensus.
Just my 2 satoshis.
Well, Britain's effectively two parties and the current coalition is the first in a long time. You don't get people frothing at the mouth at each other.
Having said that, the most rabidly right wing Brit would probably be regarded as a commie pinko begging to be relieved of their life by their American counterpart.