@lovemenorca YABU and rude.
If you are so secure in your choice to do this. Tell everyone you know NOT to give you a card, and if they do, you will chuck it in the recycling, without even opening it.
But I am willing to bet that you won't do that. I am also willing to bet that if you were in a group (or an office,) with 8 or 10 people or so, and you were the ONLY one to not be given a card, you would sulk. (Probably because that means you can't get to throw it in the trash, like a spoilt ungrateful brat.)
And it's not just 'the aged' who like cards FGS. My 2 sets of neighbours - both in their late 20s and early 30s like them too. In fact, the 27 y.o in the younger couple MAKES her own Christmas cards.
And I know loads of others who like them, send them, and appreciate them too. (who aren't AGED!)
What a ridiculous generalisation! 
It's the height of bad manners, and arrogance to dump it in the recycling as soon as you get it. What a nasty thing to do. 
Although, like some posters have said, I am questioning the validity of the claims from the OP (and a few other posters) that they bin the cards before opening them. And as for the poster saying they have a 'phobia' of Christmas cards..... Oh PLEASE!!!!!!!!!
I call bullshit on a few comments on here... 