Rejoining EASA would require accepting the ECJ as the final arbiter for anything in the aviation sector. That seems impossible for UK internal political reasons. There is no ill will towards the UK, the license acceptance issue is just a logical result of the rules in place, mostly lead developed by the UK when it was a member state. But unlike the UK, the EU actually has written constitutional treaties and law derived from those and of course has to follow them. Common sense can only be applied at the political level where rules are formulated and put into place, everything below that is purely rule based.