Isn't there an argument that goes something like "for the greater good"? I am not arguing for or against that, just wondering.
For me, the biggest disappointment of this out come was that 3 of the culprits had previously received suspended sentences for, I think, offences committed at Heathrow. Those 3 should have gone away as they had proved that they can scoff at suspended sentences. Perhaps their lenient treatment may send a message to all the others that they need not worry about the suspended sentence and may encourage them to chance their arms again in a future breach.