It is more to do with overseas ports; if Monarch owe landing fees, eurocontrol fees, fuel bills etc and one of their planes lands in their creditor's country then there is no way that it will be leaving in a hurry. The creditor would get a lien put on the airframe as quickly as they could get into the courthouse.
This will have happened in the UK too - but it is much easier for UK based administrators to deal with UK assets in a UK court than it is to have them stranded throughout Europe.