[quote DisgruntledGuineaPig]@Miljea is right- Christmas isn't one day, its the focal point of winter in the UK. Other religions have important events that dont have the same effect on the whole society, regardless of how religious the country is.
Even the most "its just one day" people do tend to think about Christmas before 24th December.
And it is the one day when most families get together in a group, outside of weddings, baptisms, "significant" birthday parties, funerals - off of which have been cancelled/forced into small numbers this year.
Our economy is set up on the understanding people will spend a lot of their yearly disposal income in December. Losing that is a massive blow to businesses that have had a shit year. [/quote]
The worst hit it is the economic one.
But a year without frantic shopping in packed out stores and office Christmas parties is a welcome miss to a lot of people. Christmas is very stressful for loads of people and a quieter Christmas will be welcomed for them.
Ultimately who and how many people spend Christmas Day with is up to them, but it's their own family's safety they need to bear in mind. It's one thing isolating for a week or two before the 25th so you can see your parents on Christmas Day. It's another doing what you want through December and then meeting up with your entire family on Christmas Eve/Day/Boxing Day. People who do that are putting their family at risk and will lead to more lockdown in Jan/Feb, driving a new wave of infections.
The elephant in the room as well is New Year's Eve. Meeting close relatives for Christmas dinner isn't so bad. Huge parties or big gatherings on New Year's Eve is.