The English had an empire. Anyone who had an empire is going to be hated.

English rulers have not always made the best of all possible decisions down through history.

The English are in fact a unique race; their history is that of a people who should have died out centuries ago.

There are English arseholes just as there are Welsh or Australian arseholes.
Most of the rest of us haven't had an empire though, so English arseholes tend to be a tad more so.