Although I agree, I’m fairly sure there would be an equal outcry if it was implemented with immediate effect.
Indeed. Someone wishing to sneak into the UK with Covid would certainly have been miffed. Giving them a few days grace, just to dampen outcry, seems a little gutless of HMG.
That said, 4 days versus no days....they either had their tickets booked or not, so the level of outcry wouldn't be too dissimilar.
All in all....this has the imperative of Saint Augustine written all over it.