It sounds like EASA are only doing what the FAA has always done - protect their own. I don't not want to defend EASA, but it has to be said that the FAA do not allow foreign reg aircraft to operate in the US unless on a temporary basis.
The same is for aircrew & engineering licences - they have to be converted, and in the case of the engineering licence the FAA do not allow any dispensation for already holding any form of EASA or CAA licence.
So can you really blame EASA for just copying the FAA's policy?