On travel and holidays people aren’t rational. Watch the ITV Heathrow programme - people having a go at airport staff because other Governments banned travel from the UK. When the inevitable happens and May/June holidays are cancelled it’ll be the airlines/operators that get the blame for ‘ruining summers’. Anyone that thinks there will be a substantial number of destinations available to visit in the near future, especially in Europe, is living in cloud cuckoo land.
So my view is Jet2 are doing the right, sensible and most sustainable thing