Why should you be allowed to use your FAA ticket without any form of validation or periodic checking to operate aircraft maintained (or not) to unpoliced/unpoliceable standards for as long as you wish?
If you bring an EU registered car into the UK you are only allowed to keep it here for a limited time before doing the honest thing and registering it locally. You have to obtain a UK driving licence after, I think, a year. Why should you be able to keep a non Eu reg aircraft here indefinately with no way for the national authority to have any jurisdiction over its maintenance or use?
Sounds fine to me.