Slightly unfair you say... really
As I say, I think your perspective on this is entirely coloured by your privileged perosonal position. It's very easy for you to seek to place additional limitations on Christmas, because essentially they don't affect you at all. I get it, that you are unable to have your parents around, but to be frank a) they have each other and b) they are in an obvious at risk category and to that extent that's a matter of self interest in any case. I'm also sure the fact that they are "A stones throw away" has also enabled you to have limited contact and the security that you are there should they need you.
This morning you accuse the Government of "Back Tracking" yet their advice has been consistent and clear. The information on the .gov website dating back to 3rd December advises that families should consider alternatives (such as Skype etc..) and reflect on the risks. There's a fine line between providing sensible advice and pushing the negatives and essentially putting the mockers on the whole thing.
They've made a decision regarding Christmas... Yes, the doom and gloom scientists (as ever) want to try and steel the limelight and put a dampner on everything... Chris Whitty is like the ** Grim Reaper, but the balance is just about right. It's not the time of year for leaving people isolated and alone where possible, whether that be for five days or two.
Frankly, I think the chance to recharge out batteries from the whole Covid Fatigue for a few days, will actually serve to improve the situation in the long term. The alternative, as I see it, would be a major breakdown in compliance, leading to significantly more death and economic damage...
Further Covid Guidelines