As Dave says, he's made a mistake.
The law has prosecuted him and he's paid the statutory penalty placed on him by the judge. No doubt the CAA have also offered him 'appropriate' advice and he's been placed under no illusions about the seriousness of the offence and what he has to do in the future to ensure his own safety and the safety of others.
If we took everyone's licence off them after a mistake had been made, there would be NO ONE still flying. Every mistake is potentially one which could lead to endangering someone, but fortunately in most cases the circumstances mean that this does not happen.
Aviation safety improvement only works if there is a 'just' culture, where genuine errors are addressed in a manner where people are not afraid to report things. The 'hang them high' brigade have no place in that culture and are just as much of a danger to aviation safety. If there is negligence or deliberate flouting of the rules, then the law can come in to force. Which is what happened here it seems.