I would never see anyone I knew on their own on Christmas Day.
However in my own experience, the people that think others should “just” lay one more place at the table or open up their homes and absorb them into their Christmas, are the same type of people that hardly ever offer to host, almost never have had the stress (and expense) of hosting for 6, 10, 12, 14+ people.
Yeah sure - They might offer a bit of money to contribute towards something that the host will inevitably have to organise, order, cook, etc, or bring a bottle of wine if you’re lucky, but they get to rock up on Christmas Day to find their day done for them, completely oblivious to the amount of shopping, ordering, arranging deliveries, preparation, cooking, cleaning and general effort it takes - because they’ve hardly, if ever, done it themselves. And it’s rarely reciprocated.
As the person who is expected to “just do that one or two extra plates” every time, it gets extremely wearing.