For me, the problem is they said they would follow the science on this travel issue. Have a criteria and stick to it. But it is clear they are not doing that. If there is a scientific fact that makes their policy correct then I’m happy to follow it. But the idea that a flight is safe if it goes to Cornwall but not to Malta (with less cases and higher vaccine rate) is preposterous. They might as well just go back to the complete ban on travel.
Once people start to see their friends abroad are vaccinated and travelling freely with no issues they will start to question why the U.K. is not allowing them to do the same.
If the Gov plans to go for Australian style approach then it should be clear. Even Australia is struggling to come up with an exit strategy for their plan.