But it's been very secular for years.
There are still lots of religious aspects to it for those who want to celebrate it as a Christian feast - advent preparations, carol services, Christmas Day services, the 12 Days celebrations...
There were always gifts - the 3 wise men arrived with gifts on 12th night (in the middle of march), as well as the shepherds on the night.
Candles and fire have always played a big part in it.
Even in our multidenopminational school (where the DCs learned about festivals for many faiths, but actively celebrate none - so it is a Wintersong gathering in the schoolyard on breakup day), they learned all about Christmas and the nativity story. As well as about the presents that happen in Hannukk'ah (sp?). And the importance of family to many faiths.
But there have been more non-religious aspects for many years as well. Cards go back more than 100 years, and presents go back a lot longer than that. Gathering for a big feast in the depths of winter was something that even pre-dated the Christian festival, as the solstice is just a few days before Christmas which was formerly the focus.
And there are a lot of different ways to celebrate Christmas. Some are more religious than others, but even among those who do recognise the nativity and its importance, there are different levels of celebration. For example, it is very important to Jehovah's Witnesses, but they have no presents at all. Whereas Catholics, Protestants, Methodists etc all exchange presents - but there may be a greater focus on useful items and hand/homemade items in the Protestant/Methodist communities than the Catholic communities based on their fundamental ethos.
None of the ways people celebrate are wrong. They have different priorities in their lives. They have different family or local traditions. They have different budgets to live within.