From the BBC

Géraldine Allot is a primary school teacher currently visiting her family in Embrun in the French Alps; she is trying to adjust her travel plans as a result of the UK's quarantine announcement.

“I am disgusted,” she told the BBC. She and her family are having to change all their travel plans. She needs to be at school meetings on 1 September ahead of the new term.
Obviously, none of the blame of travelling during a world-wide pandemic should fall on her. I understand her anger, but she only has herself to blame.

I find it a bit crazy that people are spending money on things that may be cancelled in a flash, that's their prerogative, but to blame Governments for doing the "right thing" is wrong. I don't think the borders should have been re-opened this soon, and having "travel corridors" when people are only allowed to meet outdoors in the UK or with one single household, seems a bit contradictory. But, as the Government (UK) seem hell-bent on being reactionary and not pre-emptive (New Zealand) then I suspect a lot of people will continue to lose a lot of money on a knowingly fluid situation.