Islamonut murder is one way to get your 15 mins of fame.
Horrific though it is, I suppose it could have been even worse. If the murderers had been determined to maximise the carnage, they could easily have left the street littered with dismembered corpses, but it seems that after murdering some squaddie these gentlemen were content to pose for photos, wait for Plod and then launch a hopeless attack, knowing that Plod almost certainly had guns and would know how to use them.
This horror illustrates a point many have made for years: that if you are determined to murder, you don't need to spend any time in training camps in Pakistan, Afghanistan, Somalia or any other exotic location. Given the will, the ruthlessness and easily available weapons, anyone can commit an atrocity.