I donīt know about the UK, but in Germany you canīt be penalized for one offence more than once. As a pilot, you can and you are.
Not being able to go airside is the second penalty
Actually, no, it is not.
An airside pass, like your drivers license, pilots license, etc, is not a given right, it is an obtained privilege, and losing it as a consequense of you beeing convicted does not count as a second penalty, as it is a loss of privileges, not a loss of rights.
...as it should be...